/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.widget; import com.android.internal.R; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.drawable.Drawable; import android.os.Parcel; import android.os.Parcelable; import android.util.AttributeSet; import android.view.Gravity; import android.view.ViewDebug; import android.view.accessibility.AccessibilityEvent; /** *

* A button with two states, checked and unchecked. When the button is pressed * or clicked, the state changes automatically. *

* *

XML attributes

*

* See {@link android.R.styleable#CompoundButton * CompoundButton Attributes}, {@link android.R.styleable#Button Button * Attributes}, {@link android.R.styleable#TextView TextView Attributes}, {@link * android.R.styleable#View View Attributes} *

*/ public abstract class CompoundButton extends Button implements Checkable { private boolean mChecked; private int mButtonResource; private boolean mBroadcasting; private Drawable mButtonDrawable; private OnCheckedChangeListener mOnCheckedChangeListener; private OnCheckedChangeListener mOnCheckedChangeWidgetListener; private static final int[] CHECKED_STATE_SET = { R.attr.state_checked }; public CompoundButton(Context context) { this(context, null); } public CompoundButton(Context context, AttributeSet attrs) { this(context, attrs, 0); } public CompoundButton(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); TypedArray a = context.obtainStyledAttributes( attrs, com.android.internal.R.styleable.CompoundButton, defStyle, 0); Drawable d = a.getDrawable(com.android.internal.R.styleable.CompoundButton_button); if (d != null) { setButtonDrawable(d); } boolean checked = a .getBoolean(com.android.internal.R.styleable.CompoundButton_checked, false); setChecked(checked); a.recycle(); } public void toggle() { setChecked(!mChecked); } @Override public boolean performClick() { /* * XXX: These are tiny, need some surrounding 'expanded touch area', * which will need to be implemented in Button if we only override * performClick() */ /* When clicked, toggle the state */ toggle(); return super.performClick(); } @ViewDebug.ExportedProperty public boolean isChecked() { return mChecked; } /** *

Changes the checked state of this button.

* * @param checked true to check the button, false to uncheck it */ public void setChecked(boolean checked) { if (mChecked != checked) { mChecked = checked; refreshDrawableState(); // Avoid infinite recursions if setChecked() is called from a listener if (mBroadcasting) { return; } mBroadcasting = true; if (mOnCheckedChangeListener != null) { mOnCheckedChangeListener.onCheckedChanged(this, mChecked); } if (mOnCheckedChangeWidgetListener != null) { mOnCheckedChangeWidgetListener.onCheckedChanged(this, mChecked); } mBroadcasting = false; } } /** * Register a callback to be invoked when the checked state of this button * changes. * * @param listener the callback to call on checked state change */ public void setOnCheckedChangeListener(OnCheckedChangeListener listener) { mOnCheckedChangeListener = listener; } /** * Register a callback to be invoked when the checked state of this button * changes. This callback is used for internal purpose only. * * @param listener the callback to call on checked state change * @hide */ void setOnCheckedChangeWidgetListener(OnCheckedChangeListener listener) { mOnCheckedChangeWidgetListener = listener; } /** * Interface definition for a callback to be invoked when the checked state * of a compound button changed. */ public static interface OnCheckedChangeListener { /** * Called when the checked state of a compound button has changed. * * @param buttonView The compound button view whose state has changed. * @param isChecked The new checked state of buttonView. */ void onCheckedChanged(CompoundButton buttonView, boolean isChecked); } /** * Set the background to a given Drawable, identified by its resource id. * * @param resid the resource id of the drawable to use as the background */ public void setButtonDrawable(int resid) { if (resid != 0 && resid == mButtonResource) { return; } mButtonResource = resid; Drawable d = null; if (mButtonResource != 0) { d = getResources().getDrawable(mButtonResource); } setButtonDrawable(d); } /** * Set the background to a given Drawable * * @param d The Drawable to use as the background */ public void setButtonDrawable(Drawable d) { if (d != null) { if (mButtonDrawable != null) { mButtonDrawable.setCallback(null); unscheduleDrawable(mButtonDrawable); } d.setCallback(this); d.setState(getDrawableState()); d.setVisible(getVisibility() == VISIBLE, false); mButtonDrawable = d; mButtonDrawable.setState(null); setMinHeight(mButtonDrawable.getIntrinsicHeight()); } refreshDrawableState(); } @Override public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { boolean populated = super.dispatchPopulateAccessibilityEvent(event); if (!populated) { int resourceId = 0; if (mChecked) { resourceId = R.string.accessibility_compound_button_selected; } else { resourceId = R.string.accessibility_compound_button_unselected; } String state = getResources().getString(resourceId); event.getText().add(state); event.setChecked(mChecked); } return populated; } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); final Drawable buttonDrawable = mButtonDrawable; if (buttonDrawable != null) { final int verticalGravity = getGravity() & Gravity.VERTICAL_GRAVITY_MASK; final int height = buttonDrawable.getIntrinsicHeight(); int y = 0; switch (verticalGravity) { case Gravity.BOTTOM: y = getHeight() - height; break; case Gravity.CENTER_VERTICAL: y = (getHeight() - height) / 2; break; } buttonDrawable.setBounds(0, y, buttonDrawable.getIntrinsicWidth(), y + height); buttonDrawable.draw(canvas); } } @Override protected int[] onCreateDrawableState(int extraSpace) { final int[] drawableState = super.onCreateDrawableState(extraSpace + 1); if (isChecked()) { mergeDrawableStates(drawableState, CHECKED_STATE_SET); } return drawableState; } @Override protected void drawableStateChanged() { super.drawableStateChanged(); if (mButtonDrawable != null) { int[] myDrawableState = getDrawableState(); // Set the state of the Drawable mButtonDrawable.setState(myDrawableState); invalidate(); } } @Override protected boolean verifyDrawable(Drawable who) { return super.verifyDrawable(who) || who == mButtonDrawable; } static class SavedState extends BaseSavedState { boolean checked; /** * Constructor called from {@link CompoundButton#onSaveInstanceState()} */ SavedState(Parcelable superState) { super(superState); } /** * Constructor called from {@link #CREATOR} */ private SavedState(Parcel in) { super(in); checked = (Boolean)in.readValue(null); } @Override public void writeToParcel(Parcel out, int flags) { super.writeToParcel(out, flags); out.writeValue(checked); } @Override public String toString() { return "CompoundButton.SavedState{" + Integer.toHexString(System.identityHashCode(this)) + " checked=" + checked + "}"; } public static final Parcelable.Creator CREATOR = new Parcelable.Creator() { public SavedState createFromParcel(Parcel in) { return new SavedState(in); } public SavedState[] newArray(int size) { return new SavedState[size]; } }; } @Override public Parcelable onSaveInstanceState() { // Force our ancestor class to save its state setFreezesText(true); Parcelable superState = super.onSaveInstanceState(); SavedState ss = new SavedState(superState); ss.checked = isChecked(); return ss; } @Override public void onRestoreInstanceState(Parcelable state) { SavedState ss = (SavedState) state; super.onRestoreInstanceState(ss.getSuperState()); setChecked(ss.checked); requestLayout(); } }