1401 lines
43 KiB
Java
1401 lines
43 KiB
Java
/*
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* Copyright (C) 2007 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package android.widget;
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import com.android.internal.R;
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import android.annotation.Widget;
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import android.content.Context;
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import android.content.res.TypedArray;
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import android.graphics.Rect;
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import android.util.AttributeSet;
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import android.util.Log;
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import android.view.GestureDetector;
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import android.view.Gravity;
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import android.view.HapticFeedbackConstants;
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import android.view.KeyEvent;
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import android.view.MotionEvent;
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import android.view.View;
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import android.view.ViewConfiguration;
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import android.view.ViewGroup;
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import android.view.SoundEffectConstants;
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import android.view.ContextMenu.ContextMenuInfo;
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import android.view.animation.Transformation;
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/**
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* A view that shows items in a center-locked, horizontally scrolling list.
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* <p>
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* The default values for the Gallery assume you will be using
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* {@link android.R.styleable#Theme_galleryItemBackground} as the background for
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* each View given to the Gallery from the Adapter. If you are not doing this,
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* you may need to adjust some Gallery properties, such as the spacing.
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* <p>
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* Views given to the Gallery should use {@link Gallery.LayoutParams} as their
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* layout parameters type.
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*
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* <p>See the <a href="{@docRoot}resources/tutorials/views/hello-gallery.html">Gallery
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* tutorial</a>.</p>
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*
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* @attr ref android.R.styleable#Gallery_animationDuration
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* @attr ref android.R.styleable#Gallery_spacing
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* @attr ref android.R.styleable#Gallery_gravity
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*/
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@Widget
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public class Gallery extends AbsSpinner implements GestureDetector.OnGestureListener {
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private static final String TAG = "Gallery";
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private static final boolean localLOGV = false;
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/**
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* Duration in milliseconds from the start of a scroll during which we're
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* unsure whether the user is scrolling or flinging.
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*/
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private static final int SCROLL_TO_FLING_UNCERTAINTY_TIMEOUT = 250;
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/**
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* Horizontal spacing between items.
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*/
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private int mSpacing = 0;
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/**
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* How long the transition animation should run when a child view changes
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* position, measured in milliseconds.
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*/
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private int mAnimationDuration = 400;
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/**
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* The alpha of items that are not selected.
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*/
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private float mUnselectedAlpha;
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/**
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* Left most edge of a child seen so far during layout.
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*/
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private int mLeftMost;
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/**
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* Right most edge of a child seen so far during layout.
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*/
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private int mRightMost;
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private int mGravity;
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/**
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* Helper for detecting touch gestures.
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*/
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private GestureDetector mGestureDetector;
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/**
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* The position of the item that received the user's down touch.
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*/
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private int mDownTouchPosition;
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/**
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* The view of the item that received the user's down touch.
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*/
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private View mDownTouchView;
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/**
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* Executes the delta scrolls from a fling or scroll movement.
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*/
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private FlingRunnable mFlingRunnable = new FlingRunnable();
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/**
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* Sets mSuppressSelectionChanged = false. This is used to set it to false
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* in the future. It will also trigger a selection changed.
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*/
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private Runnable mDisableSuppressSelectionChangedRunnable = new Runnable() {
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public void run() {
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mSuppressSelectionChanged = false;
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selectionChanged();
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}
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};
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/**
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* When fling runnable runs, it resets this to false. Any method along the
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* path until the end of its run() can set this to true to abort any
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* remaining fling. For example, if we've reached either the leftmost or
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* rightmost item, we will set this to true.
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*/
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private boolean mShouldStopFling;
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/**
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* The currently selected item's child.
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*/
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private View mSelectedChild;
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/**
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* Whether to continuously callback on the item selected listener during a
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* fling.
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*/
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private boolean mShouldCallbackDuringFling = true;
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/**
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* Whether to callback when an item that is not selected is clicked.
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*/
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private boolean mShouldCallbackOnUnselectedItemClick = true;
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/**
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* If true, do not callback to item selected listener.
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*/
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private boolean mSuppressSelectionChanged;
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/**
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* If true, we have received the "invoke" (center or enter buttons) key
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* down. This is checked before we action on the "invoke" key up, and is
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* subsequently cleared.
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*/
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private boolean mReceivedInvokeKeyDown;
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private AdapterContextMenuInfo mContextMenuInfo;
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/**
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* If true, this onScroll is the first for this user's drag (remember, a
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* drag sends many onScrolls).
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*/
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private boolean mIsFirstScroll;
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public Gallery(Context context) {
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this(context, null);
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}
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public Gallery(Context context, AttributeSet attrs) {
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this(context, attrs, R.attr.galleryStyle);
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}
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public Gallery(Context context, AttributeSet attrs, int defStyle) {
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super(context, attrs, defStyle);
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mGestureDetector = new GestureDetector(context, this);
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mGestureDetector.setIsLongpressEnabled(true);
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TypedArray a = context.obtainStyledAttributes(
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attrs, com.android.internal.R.styleable.Gallery, defStyle, 0);
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int index = a.getInt(com.android.internal.R.styleable.Gallery_gravity, -1);
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if (index >= 0) {
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setGravity(index);
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}
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int animationDuration =
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a.getInt(com.android.internal.R.styleable.Gallery_animationDuration, -1);
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if (animationDuration > 0) {
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setAnimationDuration(animationDuration);
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}
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int spacing =
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a.getDimensionPixelOffset(com.android.internal.R.styleable.Gallery_spacing, 0);
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setSpacing(spacing);
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float unselectedAlpha = a.getFloat(
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com.android.internal.R.styleable.Gallery_unselectedAlpha, 0.5f);
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setUnselectedAlpha(unselectedAlpha);
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a.recycle();
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// We draw the selected item last (because otherwise the item to the
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// right overlaps it)
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mGroupFlags |= FLAG_USE_CHILD_DRAWING_ORDER;
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mGroupFlags |= FLAG_SUPPORT_STATIC_TRANSFORMATIONS;
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}
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/**
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* Whether or not to callback on any {@link #getOnItemSelectedListener()}
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* while the items are being flinged. If false, only the final selected item
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* will cause the callback. If true, all items between the first and the
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* final will cause callbacks.
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*
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* @param shouldCallback Whether or not to callback on the listener while
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* the items are being flinged.
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*/
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public void setCallbackDuringFling(boolean shouldCallback) {
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mShouldCallbackDuringFling = shouldCallback;
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}
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/**
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* Whether or not to callback when an item that is not selected is clicked.
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* If false, the item will become selected (and re-centered). If true, the
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* {@link #getOnItemClickListener()} will get the callback.
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*
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* @param shouldCallback Whether or not to callback on the listener when a
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* item that is not selected is clicked.
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* @hide
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*/
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public void setCallbackOnUnselectedItemClick(boolean shouldCallback) {
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mShouldCallbackOnUnselectedItemClick = shouldCallback;
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}
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/**
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* Sets how long the transition animation should run when a child view
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* changes position. Only relevant if animation is turned on.
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*
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* @param animationDurationMillis The duration of the transition, in
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* milliseconds.
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*
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* @attr ref android.R.styleable#Gallery_animationDuration
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*/
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public void setAnimationDuration(int animationDurationMillis) {
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mAnimationDuration = animationDurationMillis;
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}
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/**
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* Sets the spacing between items in a Gallery
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*
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* @param spacing The spacing in pixels between items in the Gallery
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*
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* @attr ref android.R.styleable#Gallery_spacing
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*/
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public void setSpacing(int spacing) {
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mSpacing = spacing;
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}
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/**
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* Sets the alpha of items that are not selected in the Gallery.
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*
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* @param unselectedAlpha the alpha for the items that are not selected.
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*
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* @attr ref android.R.styleable#Gallery_unselectedAlpha
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*/
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public void setUnselectedAlpha(float unselectedAlpha) {
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mUnselectedAlpha = unselectedAlpha;
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}
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@Override
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protected boolean getChildStaticTransformation(View child, Transformation t) {
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t.clear();
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t.setAlpha(child == mSelectedChild ? 1.0f : mUnselectedAlpha);
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return true;
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}
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@Override
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protected int computeHorizontalScrollExtent() {
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// Only 1 item is considered to be selected
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return 1;
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}
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@Override
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protected int computeHorizontalScrollOffset() {
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// Current scroll position is the same as the selected position
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return mSelectedPosition;
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}
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@Override
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protected int computeHorizontalScrollRange() {
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// Scroll range is the same as the item count
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return mItemCount;
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}
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@Override
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protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
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return p instanceof LayoutParams;
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}
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@Override
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protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
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return new LayoutParams(p);
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}
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@Override
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public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
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return new LayoutParams(getContext(), attrs);
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}
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@Override
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protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
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/*
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* Gallery expects Gallery.LayoutParams.
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*/
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return new Gallery.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
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ViewGroup.LayoutParams.WRAP_CONTENT);
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}
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@Override
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protected void onLayout(boolean changed, int l, int t, int r, int b) {
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super.onLayout(changed, l, t, r, b);
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/*
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* Remember that we are in layout to prevent more layout request from
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* being generated.
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*/
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mInLayout = true;
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layout(0, false);
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mInLayout = false;
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}
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@Override
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int getChildHeight(View child) {
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return child.getMeasuredHeight();
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}
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/**
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* Tracks a motion scroll. In reality, this is used to do just about any
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* movement to items (touch scroll, arrow-key scroll, set an item as selected).
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*
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* @param deltaX Change in X from the previous event.
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*/
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void trackMotionScroll(int deltaX) {
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if (getChildCount() == 0) {
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return;
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}
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boolean toLeft = deltaX < 0;
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int limitedDeltaX = getLimitedMotionScrollAmount(toLeft, deltaX);
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if (limitedDeltaX != deltaX) {
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// The above call returned a limited amount, so stop any scrolls/flings
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mFlingRunnable.endFling(false);
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onFinishedMovement();
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}
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offsetChildrenLeftAndRight(limitedDeltaX);
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detachOffScreenChildren(toLeft);
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if (toLeft) {
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// If moved left, there will be empty space on the right
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fillToGalleryRight();
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} else {
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// Similarly, empty space on the left
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fillToGalleryLeft();
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}
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// Clear unused views
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mRecycler.clear();
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setSelectionToCenterChild();
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invalidate();
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}
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int getLimitedMotionScrollAmount(boolean motionToLeft, int deltaX) {
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int extremeItemPosition = motionToLeft ? mItemCount - 1 : 0;
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View extremeChild = getChildAt(extremeItemPosition - mFirstPosition);
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if (extremeChild == null) {
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return deltaX;
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}
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int extremeChildCenter = getCenterOfView(extremeChild);
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int galleryCenter = getCenterOfGallery();
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if (motionToLeft) {
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if (extremeChildCenter <= galleryCenter) {
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// The extreme child is past his boundary point!
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return 0;
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}
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} else {
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if (extremeChildCenter >= galleryCenter) {
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// The extreme child is past his boundary point!
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return 0;
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}
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}
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int centerDifference = galleryCenter - extremeChildCenter;
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return motionToLeft
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? Math.max(centerDifference, deltaX)
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: Math.min(centerDifference, deltaX);
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}
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/**
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* Offset the horizontal location of all children of this view by the
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* specified number of pixels.
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*
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* @param offset the number of pixels to offset
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*/
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private void offsetChildrenLeftAndRight(int offset) {
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for (int i = getChildCount() - 1; i >= 0; i--) {
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getChildAt(i).offsetLeftAndRight(offset);
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}
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}
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/**
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* @return The center of this Gallery.
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*/
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private int getCenterOfGallery() {
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return (getWidth() - mPaddingLeft - mPaddingRight) / 2 + mPaddingLeft;
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}
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/**
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* @return The center of the given view.
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*/
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private static int getCenterOfView(View view) {
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return view.getLeft() + view.getWidth() / 2;
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}
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/**
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* Detaches children that are off the screen (i.e.: Gallery bounds).
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*
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* @param toLeft Whether to detach children to the left of the Gallery, or
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* to the right.
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*/
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private void detachOffScreenChildren(boolean toLeft) {
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int numChildren = getChildCount();
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int firstPosition = mFirstPosition;
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int start = 0;
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int count = 0;
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if (toLeft) {
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final int galleryLeft = mPaddingLeft;
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for (int i = 0; i < numChildren; i++) {
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final View child = getChildAt(i);
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if (child.getRight() >= galleryLeft) {
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break;
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} else {
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count++;
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mRecycler.put(firstPosition + i, child);
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}
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}
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} else {
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final int galleryRight = getWidth() - mPaddingRight;
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for (int i = numChildren - 1; i >= 0; i--) {
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final View child = getChildAt(i);
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if (child.getLeft() <= galleryRight) {
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break;
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} else {
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start = i;
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count++;
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mRecycler.put(firstPosition + i, child);
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}
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}
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}
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detachViewsFromParent(start, count);
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if (toLeft) {
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mFirstPosition += count;
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}
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}
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/**
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* Scrolls the items so that the selected item is in its 'slot' (its center
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* is the gallery's center).
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*/
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private void scrollIntoSlots() {
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if (getChildCount() == 0 || mSelectedChild == null) return;
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int selectedCenter = getCenterOfView(mSelectedChild);
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int targetCenter = getCenterOfGallery();
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int scrollAmount = targetCenter - selectedCenter;
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if (scrollAmount != 0) {
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mFlingRunnable.startUsingDistance(scrollAmount);
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} else {
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onFinishedMovement();
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}
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}
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private void onFinishedMovement() {
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if (mSuppressSelectionChanged) {
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mSuppressSelectionChanged = false;
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// We haven't been callbacking during the fling, so do it now
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super.selectionChanged();
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}
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invalidate();
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}
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@Override
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void selectionChanged() {
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if (!mSuppressSelectionChanged) {
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super.selectionChanged();
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}
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}
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/**
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* Looks for the child that is closest to the center and sets it as the
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* selected child.
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*/
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private void setSelectionToCenterChild() {
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View selView = mSelectedChild;
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if (mSelectedChild == null) return;
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int galleryCenter = getCenterOfGallery();
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// Common case where the current selected position is correct
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if (selView.getLeft() <= galleryCenter && selView.getRight() >= galleryCenter) {
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return;
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}
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// TODO better search
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int closestEdgeDistance = Integer.MAX_VALUE;
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int newSelectedChildIndex = 0;
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for (int i = getChildCount() - 1; i >= 0; i--) {
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View child = getChildAt(i);
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if (child.getLeft() <= galleryCenter && child.getRight() >= galleryCenter) {
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// This child is in the center
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newSelectedChildIndex = i;
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break;
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}
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int childClosestEdgeDistance = Math.min(Math.abs(child.getLeft() - galleryCenter),
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Math.abs(child.getRight() - galleryCenter));
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if (childClosestEdgeDistance < closestEdgeDistance) {
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closestEdgeDistance = childClosestEdgeDistance;
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newSelectedChildIndex = i;
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}
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}
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int newPos = mFirstPosition + newSelectedChildIndex;
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if (newPos != mSelectedPosition) {
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setSelectedPositionInt(newPos);
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setNextSelectedPositionInt(newPos);
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checkSelectionChanged();
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}
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}
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/**
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* Creates and positions all views for this Gallery.
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* <p>
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* We layout rarely, most of the time {@link #trackMotionScroll(int)} takes
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* care of repositioning, adding, and removing children.
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*
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* @param delta Change in the selected position. +1 means the selection is
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* moving to the right, so views are scrolling to the left. -1
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* means the selection is moving to the left.
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*/
|
|
@Override
|
|
void layout(int delta, boolean animate) {
|
|
|
|
int childrenLeft = mSpinnerPadding.left;
|
|
int childrenWidth = mRight - mLeft - mSpinnerPadding.left - mSpinnerPadding.right;
|
|
|
|
if (mDataChanged) {
|
|
handleDataChanged();
|
|
}
|
|
|
|
// Handle an empty gallery by removing all views.
|
|
if (mItemCount == 0) {
|
|
resetList();
|
|
return;
|
|
}
|
|
|
|
// Update to the new selected position.
|
|
if (mNextSelectedPosition >= 0) {
|
|
setSelectedPositionInt(mNextSelectedPosition);
|
|
}
|
|
|
|
// All views go in recycler while we are in layout
|
|
recycleAllViews();
|
|
|
|
// Clear out old views
|
|
//removeAllViewsInLayout();
|
|
detachAllViewsFromParent();
|
|
|
|
/*
|
|
* These will be used to give initial positions to views entering the
|
|
* gallery as we scroll
|
|
*/
|
|
mRightMost = 0;
|
|
mLeftMost = 0;
|
|
|
|
// Make selected view and center it
|
|
|
|
/*
|
|
* mFirstPosition will be decreased as we add views to the left later
|
|
* on. The 0 for x will be offset in a couple lines down.
|
|
*/
|
|
mFirstPosition = mSelectedPosition;
|
|
View sel = makeAndAddView(mSelectedPosition, 0, 0, true);
|
|
|
|
// Put the selected child in the center
|
|
int selectedOffset = childrenLeft + (childrenWidth / 2) - (sel.getWidth() / 2);
|
|
sel.offsetLeftAndRight(selectedOffset);
|
|
|
|
fillToGalleryRight();
|
|
fillToGalleryLeft();
|
|
|
|
// Flush any cached views that did not get reused above
|
|
mRecycler.clear();
|
|
|
|
invalidate();
|
|
checkSelectionChanged();
|
|
|
|
mDataChanged = false;
|
|
mNeedSync = false;
|
|
setNextSelectedPositionInt(mSelectedPosition);
|
|
|
|
updateSelectedItemMetadata();
|
|
}
|
|
|
|
private void fillToGalleryLeft() {
|
|
int itemSpacing = mSpacing;
|
|
int galleryLeft = mPaddingLeft;
|
|
|
|
// Set state for initial iteration
|
|
View prevIterationView = getChildAt(0);
|
|
int curPosition;
|
|
int curRightEdge;
|
|
|
|
if (prevIterationView != null) {
|
|
curPosition = mFirstPosition - 1;
|
|
curRightEdge = prevIterationView.getLeft() - itemSpacing;
|
|
} else {
|
|
// No children available!
|
|
curPosition = 0;
|
|
curRightEdge = mRight - mLeft - mPaddingRight;
|
|
mShouldStopFling = true;
|
|
}
|
|
|
|
while (curRightEdge > galleryLeft && curPosition >= 0) {
|
|
prevIterationView = makeAndAddView(curPosition, curPosition - mSelectedPosition,
|
|
curRightEdge, false);
|
|
|
|
// Remember some state
|
|
mFirstPosition = curPosition;
|
|
|
|
// Set state for next iteration
|
|
curRightEdge = prevIterationView.getLeft() - itemSpacing;
|
|
curPosition--;
|
|
}
|
|
}
|
|
|
|
private void fillToGalleryRight() {
|
|
int itemSpacing = mSpacing;
|
|
int galleryRight = mRight - mLeft - mPaddingRight;
|
|
int numChildren = getChildCount();
|
|
int numItems = mItemCount;
|
|
|
|
// Set state for initial iteration
|
|
View prevIterationView = getChildAt(numChildren - 1);
|
|
int curPosition;
|
|
int curLeftEdge;
|
|
|
|
if (prevIterationView != null) {
|
|
curPosition = mFirstPosition + numChildren;
|
|
curLeftEdge = prevIterationView.getRight() + itemSpacing;
|
|
} else {
|
|
mFirstPosition = curPosition = mItemCount - 1;
|
|
curLeftEdge = mPaddingLeft;
|
|
mShouldStopFling = true;
|
|
}
|
|
|
|
while (curLeftEdge < galleryRight && curPosition < numItems) {
|
|
prevIterationView = makeAndAddView(curPosition, curPosition - mSelectedPosition,
|
|
curLeftEdge, true);
|
|
|
|
// Set state for next iteration
|
|
curLeftEdge = prevIterationView.getRight() + itemSpacing;
|
|
curPosition++;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Obtain a view, either by pulling an existing view from the recycler or by
|
|
* getting a new one from the adapter. If we are animating, make sure there
|
|
* is enough information in the view's layout parameters to animate from the
|
|
* old to new positions.
|
|
*
|
|
* @param position Position in the gallery for the view to obtain
|
|
* @param offset Offset from the selected position
|
|
* @param x X-coordintate indicating where this view should be placed. This
|
|
* will either be the left or right edge of the view, depending on
|
|
* the fromLeft paramter
|
|
* @param fromLeft Are we posiitoning views based on the left edge? (i.e.,
|
|
* building from left to right)?
|
|
* @return A view that has been added to the gallery
|
|
*/
|
|
private View makeAndAddView(int position, int offset, int x,
|
|
boolean fromLeft) {
|
|
|
|
View child;
|
|
|
|
if (!mDataChanged) {
|
|
child = mRecycler.get(position);
|
|
if (child != null) {
|
|
// Can reuse an existing view
|
|
int childLeft = child.getLeft();
|
|
|
|
// Remember left and right edges of where views have been placed
|
|
mRightMost = Math.max(mRightMost, childLeft
|
|
+ child.getMeasuredWidth());
|
|
mLeftMost = Math.min(mLeftMost, childLeft);
|
|
|
|
// Position the view
|
|
setUpChild(child, offset, x, fromLeft);
|
|
|
|
return child;
|
|
}
|
|
}
|
|
|
|
// Nothing found in the recycler -- ask the adapter for a view
|
|
child = mAdapter.getView(position, null, this);
|
|
|
|
// Position the view
|
|
setUpChild(child, offset, x, fromLeft);
|
|
|
|
return child;
|
|
}
|
|
|
|
/**
|
|
* Helper for makeAndAddView to set the position of a view and fill out its
|
|
* layout paramters.
|
|
*
|
|
* @param child The view to position
|
|
* @param offset Offset from the selected position
|
|
* @param x X-coordintate indicating where this view should be placed. This
|
|
* will either be the left or right edge of the view, depending on
|
|
* the fromLeft paramter
|
|
* @param fromLeft Are we posiitoning views based on the left edge? (i.e.,
|
|
* building from left to right)?
|
|
*/
|
|
private void setUpChild(View child, int offset, int x, boolean fromLeft) {
|
|
|
|
// Respect layout params that are already in the view. Otherwise
|
|
// make some up...
|
|
Gallery.LayoutParams lp = (Gallery.LayoutParams)
|
|
child.getLayoutParams();
|
|
if (lp == null) {
|
|
lp = (Gallery.LayoutParams) generateDefaultLayoutParams();
|
|
}
|
|
|
|
addViewInLayout(child, fromLeft ? -1 : 0, lp);
|
|
|
|
child.setSelected(offset == 0);
|
|
|
|
// Get measure specs
|
|
int childHeightSpec = ViewGroup.getChildMeasureSpec(mHeightMeasureSpec,
|
|
mSpinnerPadding.top + mSpinnerPadding.bottom, lp.height);
|
|
int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec,
|
|
mSpinnerPadding.left + mSpinnerPadding.right, lp.width);
|
|
|
|
// Measure child
|
|
child.measure(childWidthSpec, childHeightSpec);
|
|
|
|
int childLeft;
|
|
int childRight;
|
|
|
|
// Position vertically based on gravity setting
|
|
int childTop = calculateTop(child, true);
|
|
int childBottom = childTop + child.getMeasuredHeight();
|
|
|
|
int width = child.getMeasuredWidth();
|
|
if (fromLeft) {
|
|
childLeft = x;
|
|
childRight = childLeft + width;
|
|
} else {
|
|
childLeft = x - width;
|
|
childRight = x;
|
|
}
|
|
|
|
child.layout(childLeft, childTop, childRight, childBottom);
|
|
}
|
|
|
|
/**
|
|
* Figure out vertical placement based on mGravity
|
|
*
|
|
* @param child Child to place
|
|
* @return Where the top of the child should be
|
|
*/
|
|
private int calculateTop(View child, boolean duringLayout) {
|
|
int myHeight = duringLayout ? mMeasuredHeight : getHeight();
|
|
int childHeight = duringLayout ? child.getMeasuredHeight() : child.getHeight();
|
|
|
|
int childTop = 0;
|
|
|
|
switch (mGravity) {
|
|
case Gravity.TOP:
|
|
childTop = mSpinnerPadding.top;
|
|
break;
|
|
case Gravity.CENTER_VERTICAL:
|
|
int availableSpace = myHeight - mSpinnerPadding.bottom
|
|
- mSpinnerPadding.top - childHeight;
|
|
childTop = mSpinnerPadding.top + (availableSpace / 2);
|
|
break;
|
|
case Gravity.BOTTOM:
|
|
childTop = myHeight - mSpinnerPadding.bottom - childHeight;
|
|
break;
|
|
}
|
|
return childTop;
|
|
}
|
|
|
|
@Override
|
|
public boolean onTouchEvent(MotionEvent event) {
|
|
|
|
// Give everything to the gesture detector
|
|
boolean retValue = mGestureDetector.onTouchEvent(event);
|
|
|
|
int action = event.getAction();
|
|
if (action == MotionEvent.ACTION_UP) {
|
|
// Helper method for lifted finger
|
|
onUp();
|
|
} else if (action == MotionEvent.ACTION_CANCEL) {
|
|
onCancel();
|
|
}
|
|
|
|
return retValue;
|
|
}
|
|
|
|
/**
|
|
* {@inheritDoc}
|
|
*/
|
|
public boolean onSingleTapUp(MotionEvent e) {
|
|
|
|
if (mDownTouchPosition >= 0) {
|
|
|
|
// An item tap should make it selected, so scroll to this child.
|
|
scrollToChild(mDownTouchPosition - mFirstPosition);
|
|
|
|
// Also pass the click so the client knows, if it wants to.
|
|
if (mShouldCallbackOnUnselectedItemClick || mDownTouchPosition == mSelectedPosition) {
|
|
performItemClick(mDownTouchView, mDownTouchPosition, mAdapter
|
|
.getItemId(mDownTouchPosition));
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* {@inheritDoc}
|
|
*/
|
|
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
|
|
|
|
if (!mShouldCallbackDuringFling) {
|
|
// We want to suppress selection changes
|
|
|
|
// Remove any future code to set mSuppressSelectionChanged = false
|
|
removeCallbacks(mDisableSuppressSelectionChangedRunnable);
|
|
|
|
// This will get reset once we scroll into slots
|
|
if (!mSuppressSelectionChanged) mSuppressSelectionChanged = true;
|
|
}
|
|
|
|
// Fling the gallery!
|
|
mFlingRunnable.startUsingVelocity((int) -velocityX);
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* {@inheritDoc}
|
|
*/
|
|
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
|
|
|
|
if (localLOGV) Log.v(TAG, String.valueOf(e2.getX() - e1.getX()));
|
|
|
|
/*
|
|
* Now's a good time to tell our parent to stop intercepting our events!
|
|
* The user has moved more than the slop amount, since GestureDetector
|
|
* ensures this before calling this method. Also, if a parent is more
|
|
* interested in this touch's events than we are, it would have
|
|
* intercepted them by now (for example, we can assume when a Gallery is
|
|
* in the ListView, a vertical scroll would not end up in this method
|
|
* since a ListView would have intercepted it by now).
|
|
*/
|
|
mParent.requestDisallowInterceptTouchEvent(true);
|
|
|
|
// As the user scrolls, we want to callback selection changes so related-
|
|
// info on the screen is up-to-date with the gallery's selection
|
|
if (!mShouldCallbackDuringFling) {
|
|
if (mIsFirstScroll) {
|
|
/*
|
|
* We're not notifying the client of selection changes during
|
|
* the fling, and this scroll could possibly be a fling. Don't
|
|
* do selection changes until we're sure it is not a fling.
|
|
*/
|
|
if (!mSuppressSelectionChanged) mSuppressSelectionChanged = true;
|
|
postDelayed(mDisableSuppressSelectionChangedRunnable, SCROLL_TO_FLING_UNCERTAINTY_TIMEOUT);
|
|
}
|
|
} else {
|
|
if (mSuppressSelectionChanged) mSuppressSelectionChanged = false;
|
|
}
|
|
|
|
// Track the motion
|
|
trackMotionScroll(-1 * (int) distanceX);
|
|
|
|
mIsFirstScroll = false;
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* {@inheritDoc}
|
|
*/
|
|
public boolean onDown(MotionEvent e) {
|
|
|
|
// Kill any existing fling/scroll
|
|
mFlingRunnable.stop(false);
|
|
|
|
// Get the item's view that was touched
|
|
mDownTouchPosition = pointToPosition((int) e.getX(), (int) e.getY());
|
|
|
|
if (mDownTouchPosition >= 0) {
|
|
mDownTouchView = getChildAt(mDownTouchPosition - mFirstPosition);
|
|
mDownTouchView.setPressed(true);
|
|
}
|
|
|
|
// Reset the multiple-scroll tracking state
|
|
mIsFirstScroll = true;
|
|
|
|
// Must return true to get matching events for this down event.
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Called when a touch event's action is MotionEvent.ACTION_UP.
|
|
*/
|
|
void onUp() {
|
|
|
|
if (mFlingRunnable.mScroller.isFinished()) {
|
|
scrollIntoSlots();
|
|
}
|
|
|
|
dispatchUnpress();
|
|
}
|
|
|
|
/**
|
|
* Called when a touch event's action is MotionEvent.ACTION_CANCEL.
|
|
*/
|
|
void onCancel() {
|
|
onUp();
|
|
}
|
|
|
|
/**
|
|
* {@inheritDoc}
|
|
*/
|
|
public void onLongPress(MotionEvent e) {
|
|
|
|
if (mDownTouchPosition < 0) {
|
|
return;
|
|
}
|
|
|
|
performHapticFeedback(HapticFeedbackConstants.LONG_PRESS);
|
|
long id = getItemIdAtPosition(mDownTouchPosition);
|
|
dispatchLongPress(mDownTouchView, mDownTouchPosition, id);
|
|
}
|
|
|
|
// Unused methods from GestureDetector.OnGestureListener below
|
|
|
|
/**
|
|
* {@inheritDoc}
|
|
*/
|
|
public void onShowPress(MotionEvent e) {
|
|
}
|
|
|
|
// Unused methods from GestureDetector.OnGestureListener above
|
|
|
|
private void dispatchPress(View child) {
|
|
|
|
if (child != null) {
|
|
child.setPressed(true);
|
|
}
|
|
|
|
setPressed(true);
|
|
}
|
|
|
|
private void dispatchUnpress() {
|
|
|
|
for (int i = getChildCount() - 1; i >= 0; i--) {
|
|
getChildAt(i).setPressed(false);
|
|
}
|
|
|
|
setPressed(false);
|
|
}
|
|
|
|
@Override
|
|
public void dispatchSetSelected(boolean selected) {
|
|
/*
|
|
* We don't want to pass the selected state given from its parent to its
|
|
* children since this widget itself has a selected state to give to its
|
|
* children.
|
|
*/
|
|
}
|
|
|
|
@Override
|
|
protected void dispatchSetPressed(boolean pressed) {
|
|
|
|
// Show the pressed state on the selected child
|
|
if (mSelectedChild != null) {
|
|
mSelectedChild.setPressed(pressed);
|
|
}
|
|
}
|
|
|
|
@Override
|
|
protected ContextMenuInfo getContextMenuInfo() {
|
|
return mContextMenuInfo;
|
|
}
|
|
|
|
@Override
|
|
public boolean showContextMenuForChild(View originalView) {
|
|
|
|
final int longPressPosition = getPositionForView(originalView);
|
|
if (longPressPosition < 0) {
|
|
return false;
|
|
}
|
|
|
|
final long longPressId = mAdapter.getItemId(longPressPosition);
|
|
return dispatchLongPress(originalView, longPressPosition, longPressId);
|
|
}
|
|
|
|
@Override
|
|
public boolean showContextMenu() {
|
|
|
|
if (isPressed() && mSelectedPosition >= 0) {
|
|
int index = mSelectedPosition - mFirstPosition;
|
|
View v = getChildAt(index);
|
|
return dispatchLongPress(v, mSelectedPosition, mSelectedRowId);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
private boolean dispatchLongPress(View view, int position, long id) {
|
|
boolean handled = false;
|
|
|
|
if (mOnItemLongClickListener != null) {
|
|
handled = mOnItemLongClickListener.onItemLongClick(this, mDownTouchView,
|
|
mDownTouchPosition, id);
|
|
}
|
|
|
|
if (!handled) {
|
|
mContextMenuInfo = new AdapterContextMenuInfo(view, position, id);
|
|
handled = super.showContextMenuForChild(this);
|
|
}
|
|
|
|
if (handled) {
|
|
performHapticFeedback(HapticFeedbackConstants.LONG_PRESS);
|
|
}
|
|
|
|
return handled;
|
|
}
|
|
|
|
@Override
|
|
public boolean dispatchKeyEvent(KeyEvent event) {
|
|
// Gallery steals all key events
|
|
return event.dispatch(this, null, null);
|
|
}
|
|
|
|
/**
|
|
* Handles left, right, and clicking
|
|
* @see android.view.View#onKeyDown
|
|
*/
|
|
@Override
|
|
public boolean onKeyDown(int keyCode, KeyEvent event) {
|
|
switch (keyCode) {
|
|
|
|
case KeyEvent.KEYCODE_DPAD_LEFT:
|
|
if (movePrevious()) {
|
|
playSoundEffect(SoundEffectConstants.NAVIGATION_LEFT);
|
|
}
|
|
return true;
|
|
|
|
case KeyEvent.KEYCODE_DPAD_RIGHT:
|
|
if (moveNext()) {
|
|
playSoundEffect(SoundEffectConstants.NAVIGATION_RIGHT);
|
|
}
|
|
return true;
|
|
|
|
case KeyEvent.KEYCODE_DPAD_CENTER:
|
|
case KeyEvent.KEYCODE_ENTER:
|
|
mReceivedInvokeKeyDown = true;
|
|
// fallthrough to default handling
|
|
}
|
|
|
|
return super.onKeyDown(keyCode, event);
|
|
}
|
|
|
|
@Override
|
|
public boolean onKeyUp(int keyCode, KeyEvent event) {
|
|
switch (keyCode) {
|
|
case KeyEvent.KEYCODE_DPAD_CENTER:
|
|
case KeyEvent.KEYCODE_ENTER: {
|
|
|
|
if (mReceivedInvokeKeyDown) {
|
|
if (mItemCount > 0) {
|
|
|
|
dispatchPress(mSelectedChild);
|
|
postDelayed(new Runnable() {
|
|
public void run() {
|
|
dispatchUnpress();
|
|
}
|
|
}, ViewConfiguration.getPressedStateDuration());
|
|
|
|
int selectedIndex = mSelectedPosition - mFirstPosition;
|
|
performItemClick(getChildAt(selectedIndex), mSelectedPosition, mAdapter
|
|
.getItemId(mSelectedPosition));
|
|
}
|
|
}
|
|
|
|
// Clear the flag
|
|
mReceivedInvokeKeyDown = false;
|
|
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return super.onKeyUp(keyCode, event);
|
|
}
|
|
|
|
boolean movePrevious() {
|
|
if (mItemCount > 0 && mSelectedPosition > 0) {
|
|
scrollToChild(mSelectedPosition - mFirstPosition - 1);
|
|
return true;
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
boolean moveNext() {
|
|
if (mItemCount > 0 && mSelectedPosition < mItemCount - 1) {
|
|
scrollToChild(mSelectedPosition - mFirstPosition + 1);
|
|
return true;
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
private boolean scrollToChild(int childPosition) {
|
|
View child = getChildAt(childPosition);
|
|
|
|
if (child != null) {
|
|
int distance = getCenterOfGallery() - getCenterOfView(child);
|
|
mFlingRunnable.startUsingDistance(distance);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
@Override
|
|
void setSelectedPositionInt(int position) {
|
|
super.setSelectedPositionInt(position);
|
|
|
|
// Updates any metadata we keep about the selected item.
|
|
updateSelectedItemMetadata();
|
|
}
|
|
|
|
private void updateSelectedItemMetadata() {
|
|
|
|
View oldSelectedChild = mSelectedChild;
|
|
|
|
View child = mSelectedChild = getChildAt(mSelectedPosition - mFirstPosition);
|
|
if (child == null) {
|
|
return;
|
|
}
|
|
|
|
child.setSelected(true);
|
|
child.setFocusable(true);
|
|
|
|
if (hasFocus()) {
|
|
child.requestFocus();
|
|
}
|
|
|
|
// We unfocus the old child down here so the above hasFocus check
|
|
// returns true
|
|
if (oldSelectedChild != null) {
|
|
|
|
// Make sure its drawable state doesn't contain 'selected'
|
|
oldSelectedChild.setSelected(false);
|
|
|
|
// Make sure it is not focusable anymore, since otherwise arrow keys
|
|
// can make this one be focused
|
|
oldSelectedChild.setFocusable(false);
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* Describes how the child views are aligned.
|
|
* @param gravity
|
|
*
|
|
* @attr ref android.R.styleable#Gallery_gravity
|
|
*/
|
|
public void setGravity(int gravity)
|
|
{
|
|
if (mGravity != gravity) {
|
|
mGravity = gravity;
|
|
requestLayout();
|
|
}
|
|
}
|
|
|
|
@Override
|
|
protected int getChildDrawingOrder(int childCount, int i) {
|
|
int selectedIndex = mSelectedPosition - mFirstPosition;
|
|
|
|
// Just to be safe
|
|
if (selectedIndex < 0) return i;
|
|
|
|
if (i == childCount - 1) {
|
|
// Draw the selected child last
|
|
return selectedIndex;
|
|
} else if (i >= selectedIndex) {
|
|
// Move the children to the right of the selected child earlier one
|
|
return i + 1;
|
|
} else {
|
|
// Keep the children to the left of the selected child the same
|
|
return i;
|
|
}
|
|
}
|
|
|
|
@Override
|
|
protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) {
|
|
super.onFocusChanged(gainFocus, direction, previouslyFocusedRect);
|
|
|
|
/*
|
|
* The gallery shows focus by focusing the selected item. So, give
|
|
* focus to our selected item instead. We steal keys from our
|
|
* selected item elsewhere.
|
|
*/
|
|
if (gainFocus && mSelectedChild != null) {
|
|
mSelectedChild.requestFocus(direction);
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* Responsible for fling behavior. Use {@link #startUsingVelocity(int)} to
|
|
* initiate a fling. Each frame of the fling is handled in {@link #run()}.
|
|
* A FlingRunnable will keep re-posting itself until the fling is done.
|
|
*
|
|
*/
|
|
private class FlingRunnable implements Runnable {
|
|
/**
|
|
* Tracks the decay of a fling scroll
|
|
*/
|
|
private Scroller mScroller;
|
|
|
|
/**
|
|
* X value reported by mScroller on the previous fling
|
|
*/
|
|
private int mLastFlingX;
|
|
|
|
public FlingRunnable() {
|
|
mScroller = new Scroller(getContext());
|
|
}
|
|
|
|
private void startCommon() {
|
|
// Remove any pending flings
|
|
removeCallbacks(this);
|
|
}
|
|
|
|
public void startUsingVelocity(int initialVelocity) {
|
|
if (initialVelocity == 0) return;
|
|
|
|
startCommon();
|
|
|
|
int initialX = initialVelocity < 0 ? Integer.MAX_VALUE : 0;
|
|
mLastFlingX = initialX;
|
|
mScroller.fling(initialX, 0, initialVelocity, 0,
|
|
0, Integer.MAX_VALUE, 0, Integer.MAX_VALUE);
|
|
post(this);
|
|
}
|
|
|
|
public void startUsingDistance(int distance) {
|
|
if (distance == 0) return;
|
|
|
|
startCommon();
|
|
|
|
mLastFlingX = 0;
|
|
mScroller.startScroll(0, 0, -distance, 0, mAnimationDuration);
|
|
post(this);
|
|
}
|
|
|
|
public void stop(boolean scrollIntoSlots) {
|
|
removeCallbacks(this);
|
|
endFling(scrollIntoSlots);
|
|
}
|
|
|
|
private void endFling(boolean scrollIntoSlots) {
|
|
/*
|
|
* Force the scroller's status to finished (without setting its
|
|
* position to the end)
|
|
*/
|
|
mScroller.forceFinished(true);
|
|
|
|
if (scrollIntoSlots) scrollIntoSlots();
|
|
}
|
|
|
|
public void run() {
|
|
|
|
if (mItemCount == 0) {
|
|
endFling(true);
|
|
return;
|
|
}
|
|
|
|
mShouldStopFling = false;
|
|
|
|
final Scroller scroller = mScroller;
|
|
boolean more = scroller.computeScrollOffset();
|
|
final int x = scroller.getCurrX();
|
|
|
|
// Flip sign to convert finger direction to list items direction
|
|
// (e.g. finger moving down means list is moving towards the top)
|
|
int delta = mLastFlingX - x;
|
|
|
|
// Pretend that each frame of a fling scroll is a touch scroll
|
|
if (delta > 0) {
|
|
// Moving towards the left. Use first view as mDownTouchPosition
|
|
mDownTouchPosition = mFirstPosition;
|
|
|
|
// Don't fling more than 1 screen
|
|
delta = Math.min(getWidth() - mPaddingLeft - mPaddingRight - 1, delta);
|
|
} else {
|
|
// Moving towards the right. Use last view as mDownTouchPosition
|
|
int offsetToLast = getChildCount() - 1;
|
|
mDownTouchPosition = mFirstPosition + offsetToLast;
|
|
|
|
// Don't fling more than 1 screen
|
|
delta = Math.max(-(getWidth() - mPaddingRight - mPaddingLeft - 1), delta);
|
|
}
|
|
|
|
trackMotionScroll(delta);
|
|
|
|
if (more && !mShouldStopFling) {
|
|
mLastFlingX = x;
|
|
post(this);
|
|
} else {
|
|
endFling(true);
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* Gallery extends LayoutParams to provide a place to hold current
|
|
* Transformation information along with previous position/transformation
|
|
* info.
|
|
*
|
|
*/
|
|
public static class LayoutParams extends ViewGroup.LayoutParams {
|
|
public LayoutParams(Context c, AttributeSet attrs) {
|
|
super(c, attrs);
|
|
}
|
|
|
|
public LayoutParams(int w, int h) {
|
|
super(w, h);
|
|
}
|
|
|
|
public LayoutParams(ViewGroup.LayoutParams source) {
|
|
super(source);
|
|
}
|
|
}
|
|
}
|