graphics/java/android/graphics/drawable/ScaleDrawable.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2006 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.graphics.drawable;

 import com.android.internal.R;

 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;

 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.res.Resources;
 import android.content.res.Resources.Theme;
 import android.content.res.TypedArray;
 import android.graphics.Canvas;
 import android.graphics.PixelFormat;
 import android.graphics.Rect;
 import android.util.AttributeSet;
 import android.util.TypedValue;
 import android.view.Gravity;

 import java.io.IOException;

 /**
  * A Drawable that changes the size of another Drawable based on its current
  * level value. You can control how much the child Drawable changes in width
  * and height based on the level, as well as a gravity to control where it is
  * placed in its overall container. Most often used to implement things like
  * progress bars.
  * <p>
  * The default level may be specified from XML using the
  * {@link android.R.styleable#ScaleDrawable_level android:level} property. When
  * this property is not specified, the default level is 0, which corresponds to
  * zero height and/or width depending on the values specified for
  * {@code android.R.styleable#ScaleDrawable_scaleWidth scaleWidth} and
  * {@code android.R.styleable#ScaleDrawable_scaleHeight scaleHeight}. At run
  * time, the level may be set via {@link #setLevel(int)}.
  * <p>
  * A scale drawable may be defined in an XML file with the {@code <scale>}
  * element. For more information, see the guide to
  * <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable
  * Resources</a>.
  *
  * @attr ref android.R.styleable#ScaleDrawable_scaleWidth
  * @attr ref android.R.styleable#ScaleDrawable_scaleHeight
  * @attr ref android.R.styleable#ScaleDrawable_scaleGravity
  * @attr ref android.R.styleable#ScaleDrawable_drawable
  * @attr ref android.R.styleable#ScaleDrawable_level
  */
 public class ScaleDrawable extends DrawableWrapper {
     private static final int MAX_LEVEL = 10000;

     private final Rect mTmpRect = new Rect();

     private ScaleState mState;

     ScaleDrawable() {
         this(new ScaleState(null, null), null);
     }

     /**
      * Creates a new scale drawable with the specified gravity and scale
      * properties.
      *
      * @param drawable the drawable to scale
      * @param gravity gravity constant (see {@link Gravity} used to position
      *                the scaled drawable within the parent container
      * @param scaleWidth width scaling factor [0...1] to use then the level is
      *                   at the maximum value, or -1 to not scale width
      * @param scaleHeight height scaling factor [0...1] to use then the level
      *                    is at the maximum value, or -1 to not scale height
      */
     public ScaleDrawable(Drawable drawable, int gravity, float scaleWidth, float scaleHeight) {
         this(new ScaleState(null, null), null);

         mState.mGravity = gravity;
         mState.mScaleWidth = scaleWidth;
         mState.mScaleHeight = scaleHeight;

         setDrawable(drawable);
     }

     @Override
     public void inflate(@NonNull Resources r, @NonNull XmlPullParser parser,
             @NonNull AttributeSet attrs, @Nullable Theme theme)
             throws XmlPullParserException, IOException {
         final TypedArray a = obtainAttributes(r, theme, attrs, R.styleable.ScaleDrawable);

         // Inflation will advance the XmlPullParser and AttributeSet.
         super.inflate(r, parser, attrs, theme);

         updateStateFromTypedArray(a);
         verifyRequiredAttributes(a);
         a.recycle();

         updateLocalState();
     }

     @Override
     public void applyTheme(@NonNull Theme t) {
         super.applyTheme(t);

         final ScaleState state = mState;
         if (state == null) {
             return;
         }

         if (state.mThemeAttrs != null) {
             final TypedArray a = t.resolveAttributes(state.mThemeAttrs, R.styleable.ScaleDrawable);
             try {
                 updateStateFromTypedArray(a);
                 verifyRequiredAttributes(a);
             } catch (XmlPullParserException e) {
                 rethrowAsRuntimeException(e);
             } finally {
                 a.recycle();
             }
         }

         updateLocalState();
     }

     private void verifyRequiredAttributes(@NonNull TypedArray a) throws XmlPullParserException {
         // If we're not waiting on a theme, verify required attributes.
         if (getDrawable() == null && (mState.mThemeAttrs == null
                 || mState.mThemeAttrs[R.styleable.ScaleDrawable_drawable] == 0)) {
             throw new XmlPullParserException(a.getPositionDescription()
                     + ": <scale> tag requires a 'drawable' attribute or "
                     + "child tag defining a drawable");
         }
     }

     private void updateStateFromTypedArray(@NonNull TypedArray a) {
         final ScaleState state = mState;
         if (state == null) {
             return;
         }

         // Account for any configuration changes.
         state.mChangingConfigurations |= a.getChangingConfigurations();

         // Extract the theme attributes, if any.
         state.mThemeAttrs = a.extractThemeAttrs();

         state.mScaleWidth = getPercent(a,
                 R.styleable.ScaleDrawable_scaleWidth, state.mScaleWidth);
         state.mScaleHeight = getPercent(a,
                 R.styleable.ScaleDrawable_scaleHeight, state.mScaleHeight);
         state.mGravity = a.getInt(
                 R.styleable.ScaleDrawable_scaleGravity, state.mGravity);
         state.mUseIntrinsicSizeAsMin = a.getBoolean(
                 R.styleable.ScaleDrawable_useIntrinsicSizeAsMinimum, state.mUseIntrinsicSizeAsMin);
         state.mInitialLevel = a.getInt(
                 R.styleable.ScaleDrawable_level, state.mInitialLevel);
     }

     private static float getPercent(TypedArray a, int index, float defaultValue) {
         final int type = a.getType(index);
         if (type == TypedValue.TYPE_FRACTION || type == TypedValue.TYPE_NULL) {
             return a.getFraction(index, 1, 1, defaultValue);
         }

         // Coerce to float.
         final String s = a.getString(index);
         if (s != null) {
             if (s.endsWith("%")) {
                 final String f = s.substring(0, s.length() - 1);
                 return Float.parseFloat(f) / 100.0f;
             }
         }

         return defaultValue;
     }

     @Override
     public void draw(Canvas canvas) {
         final Drawable d = getDrawable();
         if (d != null && d.getLevel() != 0) {
             d.draw(canvas);
         }
     }

     @Override
     public int getOpacity() {
         final Drawable d = getDrawable();
         if (d.getLevel() == 0) {
             return PixelFormat.TRANSPARENT;
         }

         final int opacity = d.getOpacity();
         if (opacity == PixelFormat.OPAQUE && d.getLevel() < MAX_LEVEL) {
             return PixelFormat.TRANSLUCENT;
         }

         return opacity;
     }

     @Override
     protected boolean onLevelChange(int level) {
         super.onLevelChange(level);
         onBoundsChange(getBounds());
         invalidateSelf();
         return true;
     }

     @Override
     protected void onBoundsChange(Rect bounds) {
         final Drawable d = getDrawable();
         final Rect r = mTmpRect;
         final boolean min = mState.mUseIntrinsicSizeAsMin;
         final int level = getLevel();

         int w = bounds.width();
         if (mState.mScaleWidth > 0) {
             final int iw = min ? d.getIntrinsicWidth() : 0;
             w -= (int) ((w - iw) * (MAX_LEVEL - level) * mState.mScaleWidth / MAX_LEVEL);
         }

         int h = bounds.height();
         if (mState.mScaleHeight > 0) {
             final int ih = min ? d.getIntrinsicHeight() : 0;
             h -= (int) ((h - ih) * (MAX_LEVEL - level) * mState.mScaleHeight / MAX_LEVEL);
         }

         final int layoutDirection = getLayoutDirection();
         Gravity.apply(mState.mGravity, w, h, bounds, r, layoutDirection);

         if (w > 0 && h > 0) {
             d.setBounds(r.left, r.top, r.right, r.bottom);
         }
     }

     @Override
     DrawableWrapperState mutateConstantState() {
         mState = new ScaleState(mState, null);
         return mState;
     }

     static final class ScaleState extends DrawableWrapper.DrawableWrapperState {
         /** Constant used to disable scaling for a particular dimension. */
         private static final float DO_NOT_SCALE = -1.0f;

         private int[] mThemeAttrs;

         float mScaleWidth = DO_NOT_SCALE;
         float mScaleHeight = DO_NOT_SCALE;
         int mGravity = Gravity.LEFT;
         boolean mUseIntrinsicSizeAsMin = false;
         int mInitialLevel = 0;

         ScaleState(ScaleState orig, Resources res) {
             super(orig, res);

             if (orig != null) {
                 mScaleWidth = orig.mScaleWidth;
                 mScaleHeight = orig.mScaleHeight;
                 mGravity = orig.mGravity;
                 mUseIntrinsicSizeAsMin = orig.mUseIntrinsicSizeAsMin;
                 mInitialLevel = orig.mInitialLevel;
             }
         }

         @Override
         public Drawable newDrawable(Resources res) {
             return new ScaleDrawable(this, res);
         }
     }

     /**
      * Creates a new ScaleDrawable based on the specified constant state.
      * <p>
      * The resulting drawable is guaranteed to have a new constant state.
      *
      * @param state constant state from which the drawable inherits
      */
     private ScaleDrawable(ScaleState state, Resources res) {
         super(state, res);

         mState = state;

         updateLocalState();
     }

     private void updateLocalState() {
         setLevel(mState.mInitialLevel);
     }
 }
	/*
	* Copyright (C) 2006 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.graphics.drawable;

	import com.android.internal.R;

	import org.xmlpull.v1.XmlPullParser;
	import org.xmlpull.v1.XmlPullParserException;

	import android.annotation.NonNull;
	import android.annotation.Nullable;
	import android.content.res.Resources;
	import android.content.res.Resources.Theme;
	import android.content.res.TypedArray;
	import android.graphics.Canvas;
	import android.graphics.PixelFormat;
	import android.graphics.Rect;
	import android.util.AttributeSet;
	import android.util.TypedValue;
	import android.view.Gravity;

	import java.io.IOException;

	/**
	* A Drawable that changes the size of another Drawable based on its current
	* level value. You can control how much the child Drawable changes in width
	* and height based on the level, as well as a gravity to control where it is
	* placed in its overall container. Most often used to implement things like
	* progress bars.
	* <p>
	* The default level may be specified from XML using the
	* {@link android.R.styleable#ScaleDrawable_level android:level} property. When
	* this property is not specified, the default level is 0, which corresponds to
	* zero height and/or width depending on the values specified for
	* {@code android.R.styleable#ScaleDrawable_scaleWidth scaleWidth} and
	* {@code android.R.styleable#ScaleDrawable_scaleHeight scaleHeight}. At run
	* time, the level may be set via {@link #setLevel(int)}.
	* <p>
	* A scale drawable may be defined in an XML file with the {@code <scale>}
	* element. For more information, see the guide to
	* <a href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable
	* Resources</a>.
	*
	* @attr ref android.R.styleable#ScaleDrawable_scaleWidth
	* @attr ref android.R.styleable#ScaleDrawable_scaleHeight
	* @attr ref android.R.styleable#ScaleDrawable_scaleGravity
	* @attr ref android.R.styleable#ScaleDrawable_drawable
	* @attr ref android.R.styleable#ScaleDrawable_level
	*/
	public class ScaleDrawable extends DrawableWrapper {
	private static final int MAX_LEVEL = 10000;

	private final Rect mTmpRect = new Rect();

	private ScaleState mState;

	ScaleDrawable() {
	this(new ScaleState(null, null), null);
	}

	/**
	* Creates a new scale drawable with the specified gravity and scale
	* properties.
	*
	* @param drawable the drawable to scale
	* @param gravity gravity constant (see {@link Gravity} used to position
	* the scaled drawable within the parent container
	* @param scaleWidth width scaling factor [0...1] to use then the level is
	* at the maximum value, or -1 to not scale width
	* @param scaleHeight height scaling factor [0...1] to use then the level
	* is at the maximum value, or -1 to not scale height
	*/
	public ScaleDrawable(Drawable drawable, int gravity, float scaleWidth, float scaleHeight) {
	this(new ScaleState(null, null), null);

	mState.mGravity = gravity;
	mState.mScaleWidth = scaleWidth;
	mState.mScaleHeight = scaleHeight;

	setDrawable(drawable);
	}

	@Override
	public void inflate(@NonNull Resources r, @NonNull XmlPullParser parser,
	@NonNull AttributeSet attrs, @Nullable Theme theme)
	throws XmlPullParserException, IOException {
	final TypedArray a = obtainAttributes(r, theme, attrs, R.styleable.ScaleDrawable);

	// Inflation will advance the XmlPullParser and AttributeSet.
	super.inflate(r, parser, attrs, theme);

	updateStateFromTypedArray(a);
	verifyRequiredAttributes(a);
	a.recycle();

	updateLocalState();
	}

	@Override
	public void applyTheme(@NonNull Theme t) {
	super.applyTheme(t);

	final ScaleState state = mState;
	if (state == null) {
	return;
	}

	if (state.mThemeAttrs != null) {
	final TypedArray a = t.resolveAttributes(state.mThemeAttrs, R.styleable.ScaleDrawable);
	try {
	updateStateFromTypedArray(a);
	verifyRequiredAttributes(a);
	} catch (XmlPullParserException e) {
	rethrowAsRuntimeException(e);
	} finally {
	a.recycle();
	}
	}

	updateLocalState();
	}

	private void verifyRequiredAttributes(@NonNull TypedArray a) throws XmlPullParserException {
	// If we're not waiting on a theme, verify required attributes.
	if (getDrawable() == null && (mState.mThemeAttrs == null
	\|\| mState.mThemeAttrs[R.styleable.ScaleDrawable_drawable] == 0)) {
	throw new XmlPullParserException(a.getPositionDescription()
	+ ": <scale> tag requires a 'drawable' attribute or "
	+ "child tag defining a drawable");
	}
	}

	private void updateStateFromTypedArray(@NonNull TypedArray a) {
	final ScaleState state = mState;
	if (state == null) {
	return;
	}

	// Account for any configuration changes.
	state.mChangingConfigurations \|= a.getChangingConfigurations();

	// Extract the theme attributes, if any.
	state.mThemeAttrs = a.extractThemeAttrs();

	state.mScaleWidth = getPercent(a,
	R.styleable.ScaleDrawable_scaleWidth, state.mScaleWidth);
	state.mScaleHeight = getPercent(a,
	R.styleable.ScaleDrawable_scaleHeight, state.mScaleHeight);
	state.mGravity = a.getInt(
	R.styleable.ScaleDrawable_scaleGravity, state.mGravity);
	state.mUseIntrinsicSizeAsMin = a.getBoolean(
	R.styleable.ScaleDrawable_useIntrinsicSizeAsMinimum, state.mUseIntrinsicSizeAsMin);
	state.mInitialLevel = a.getInt(
	R.styleable.ScaleDrawable_level, state.mInitialLevel);
	}

	private static float getPercent(TypedArray a, int index, float defaultValue) {
	final int type = a.getType(index);
	if (type == TypedValue.TYPE_FRACTION \|\| type == TypedValue.TYPE_NULL) {
	return a.getFraction(index, 1, 1, defaultValue);
	}

	// Coerce to float.
	final String s = a.getString(index);
	if (s != null) {
	if (s.endsWith("%")) {
	final String f = s.substring(0, s.length() - 1);
	return Float.parseFloat(f) / 100.0f;
	}
	}

	return defaultValue;
	}

	@Override
	public void draw(Canvas canvas) {
	final Drawable d = getDrawable();
	if (d != null && d.getLevel() != 0) {
	d.draw(canvas);
	}
	}

	@Override
	public int getOpacity() {
	final Drawable d = getDrawable();
	if (d.getLevel() == 0) {
	return PixelFormat.TRANSPARENT;
	}

	final int opacity = d.getOpacity();
	if (opacity == PixelFormat.OPAQUE && d.getLevel() < MAX_LEVEL) {
	return PixelFormat.TRANSLUCENT;
	}

	return opacity;
	}

	@Override
	protected boolean onLevelChange(int level) {
	super.onLevelChange(level);
	onBoundsChange(getBounds());
	invalidateSelf();
	return true;
	}

	@Override
	protected void onBoundsChange(Rect bounds) {
	final Drawable d = getDrawable();
	final Rect r = mTmpRect;
	final boolean min = mState.mUseIntrinsicSizeAsMin;
	final int level = getLevel();

	int w = bounds.width();
	if (mState.mScaleWidth > 0) {
	final int iw = min ? d.getIntrinsicWidth() : 0;
	w -= (int) ((w - iw) * (MAX_LEVEL - level) * mState.mScaleWidth / MAX_LEVEL);
	}

	int h = bounds.height();
	if (mState.mScaleHeight > 0) {
	final int ih = min ? d.getIntrinsicHeight() : 0;
	h -= (int) ((h - ih) * (MAX_LEVEL - level) * mState.mScaleHeight / MAX_LEVEL);
	}

	final int layoutDirection = getLayoutDirection();
	Gravity.apply(mState.mGravity, w, h, bounds, r, layoutDirection);

	if (w > 0 && h > 0) {
	d.setBounds(r.left, r.top, r.right, r.bottom);
	}
	}

	@Override
	DrawableWrapperState mutateConstantState() {
	mState = new ScaleState(mState, null);
	return mState;
	}

	static final class ScaleState extends DrawableWrapper.DrawableWrapperState {
	/** Constant used to disable scaling for a particular dimension. */
	private static final float DO_NOT_SCALE = -1.0f;

	private int[] mThemeAttrs;

	float mScaleWidth = DO_NOT_SCALE;
	float mScaleHeight = DO_NOT_SCALE;
	int mGravity = Gravity.LEFT;
	boolean mUseIntrinsicSizeAsMin = false;
	int mInitialLevel = 0;

	ScaleState(ScaleState orig, Resources res) {
	super(orig, res);

	if (orig != null) {
	mScaleWidth = orig.mScaleWidth;
	mScaleHeight = orig.mScaleHeight;
	mGravity = orig.mGravity;
	mUseIntrinsicSizeAsMin = orig.mUseIntrinsicSizeAsMin;
	mInitialLevel = orig.mInitialLevel;
	}
	}

	@Override
	public Drawable newDrawable(Resources res) {
	return new ScaleDrawable(this, res);
	}
	}

	/**
	* Creates a new ScaleDrawable based on the specified constant state.
	* <p>
	* The resulting drawable is guaranteed to have a new constant state.
	*
	* @param state constant state from which the drawable inherits
	*/
	private ScaleDrawable(ScaleState state, Resources res) {
	super(state, res);

	mState = state;

	updateLocalState();
	}

	private void updateLocalState() {
	setLevel(mState.mInitialLevel);
	}
	}