Java tutorial
/* * 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.graphics.drawable; import android.annotation.NonNull; import android.annotation.Nullable; import android.annotation.TestApi; import android.content.pm.ActivityInfo.Config; import android.content.res.ColorStateList; import android.content.res.Resources; import android.content.res.Resources.Theme; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.ColorFilter; import android.graphics.Outline; import android.graphics.Paint; import android.graphics.PixelFormat; import android.graphics.PorterDuff; import android.graphics.PorterDuff.Mode; import android.graphics.PorterDuffColorFilter; import android.graphics.Rect; import android.graphics.Shader; import android.graphics.Xfermode; import android.graphics.drawable.shapes.Shape; import android.util.AttributeSet; import com.android.internal.R; import org.xmlpull.v1.XmlPullParser; import org.xmlpull.v1.XmlPullParserException; import java.io.IOException; /** * A Drawable object that draws primitive shapes. A ShapeDrawable takes a * {@link android.graphics.drawable.shapes.Shape} object and manages its * presence on the screen. If no Shape is given, then the ShapeDrawable will * default to a {@link android.graphics.drawable.shapes.RectShape}. * <p> * This object can be defined in an XML file with the <code><shape></code> * element. * </p> * <div class="special reference"> <h3>Developer Guides</h3> * <p> * For more information about how to use ShapeDrawable, read the <a * href="{@docRoot}guide/topics/graphics/2d-graphics.html#shape-drawable"> * Canvas and Drawables</a> document. For more information about defining a * ShapeDrawable in XML, read the * <a href="{@docRoot}guide/topics/resources/drawable-resource.html#Shape"> * Drawable Resources</a> document. * </p> * </div> * * @attr ref android.R.styleable#ShapeDrawablePadding_left * @attr ref android.R.styleable#ShapeDrawablePadding_top * @attr ref android.R.styleable#ShapeDrawablePadding_right * @attr ref android.R.styleable#ShapeDrawablePadding_bottom * @attr ref android.R.styleable#ShapeDrawable_color * @attr ref android.R.styleable#ShapeDrawable_width * @attr ref android.R.styleable#ShapeDrawable_height */ public class ShapeDrawable extends Drawable { private @NonNull ShapeState mShapeState; private PorterDuffColorFilter mTintFilter; private boolean mMutated; /** * ShapeDrawable constructor. */ public ShapeDrawable() { this(new ShapeState(), null); } /** * Creates a ShapeDrawable with a specified Shape. * * @param s the Shape that this ShapeDrawable should be */ public ShapeDrawable(Shape s) { this(new ShapeState(), null); mShapeState.mShape = s; } /** * Returns the Shape of this ShapeDrawable. */ public Shape getShape() { return mShapeState.mShape; } /** * Sets the Shape of this ShapeDrawable. */ public void setShape(Shape s) { mShapeState.mShape = s; updateShape(); } /** * Sets a ShaderFactory to which requests for a * {@link android.graphics.Shader} object will be made. * * @param fact an instance of your ShaderFactory implementation */ public void setShaderFactory(ShaderFactory fact) { mShapeState.mShaderFactory = fact; } /** * Returns the ShaderFactory used by this ShapeDrawable for requesting a * {@link android.graphics.Shader}. */ public ShaderFactory getShaderFactory() { return mShapeState.mShaderFactory; } /** * Returns the Paint used to draw the shape. */ public Paint getPaint() { return mShapeState.mPaint; } /** * Sets padding for the shape. * * @param left padding for the left side (in pixels) * @param top padding for the top (in pixels) * @param right padding for the right side (in pixels) * @param bottom padding for the bottom (in pixels) */ public void setPadding(int left, int top, int right, int bottom) { if ((left | top | right | bottom) == 0) { mShapeState.mPadding = null; } else { if (mShapeState.mPadding == null) { mShapeState.mPadding = new Rect(); } mShapeState.mPadding.set(left, top, right, bottom); } invalidateSelf(); } /** * Sets padding for this shape, defined by a Rect object. Define the padding * in the Rect object as: left, top, right, bottom. */ public void setPadding(Rect padding) { if (padding == null) { mShapeState.mPadding = null; } else { if (mShapeState.mPadding == null) { mShapeState.mPadding = new Rect(); } mShapeState.mPadding.set(padding); } invalidateSelf(); } /** * Sets the intrinsic (default) width for this shape. * * @param width the intrinsic width (in pixels) */ public void setIntrinsicWidth(int width) { mShapeState.mIntrinsicWidth = width; invalidateSelf(); } /** * Sets the intrinsic (default) height for this shape. * * @param height the intrinsic height (in pixels) */ public void setIntrinsicHeight(int height) { mShapeState.mIntrinsicHeight = height; invalidateSelf(); } @Override public int getIntrinsicWidth() { return mShapeState.mIntrinsicWidth; } @Override public int getIntrinsicHeight() { return mShapeState.mIntrinsicHeight; } @Override public boolean getPadding(Rect padding) { if (mShapeState.mPadding != null) { padding.set(mShapeState.mPadding); return true; } else { return super.getPadding(padding); } } private static int modulateAlpha(int paintAlpha, int alpha) { int scale = alpha + (alpha >>> 7); // convert to 0..256 return paintAlpha * scale >>> 8; } /** * Called from the drawable's draw() method after the canvas has been set to * draw the shape at (0,0). Subclasses can override for special effects such * as multiple layers, stroking, etc. */ protected void onDraw(Shape shape, Canvas canvas, Paint paint) { shape.draw(canvas, paint); } @Override public void draw(Canvas canvas) { final Rect r = getBounds(); final ShapeState state = mShapeState; final Paint paint = state.mPaint; final int prevAlpha = paint.getAlpha(); paint.setAlpha(modulateAlpha(prevAlpha, state.mAlpha)); // only draw shape if it may affect output if (paint.getAlpha() != 0 || paint.getXfermode() != null || paint.hasShadowLayer()) { final boolean clearColorFilter; if (mTintFilter != null && paint.getColorFilter() == null) { paint.setColorFilter(mTintFilter); clearColorFilter = true; } else { clearColorFilter = false; } if (state.mShape != null) { // need the save both for the translate, and for the (unknown) // Shape final int count = canvas.save(); canvas.translate(r.left, r.top); onDraw(state.mShape, canvas, paint); canvas.restoreToCount(count); } else { canvas.drawRect(r, paint); } if (clearColorFilter) { paint.setColorFilter(null); } } // restore paint.setAlpha(prevAlpha); } @Override public @Config int getChangingConfigurations() { return super.getChangingConfigurations() | mShapeState.getChangingConfigurations(); } /** * Set the alpha level for this drawable [0..255]. Note that this drawable * also has a color in its paint, which has an alpha as well. These two * values are automatically combined during drawing. Thus if the color's * alpha is 75% (i.e. 192) and the drawable's alpha is 50% (i.e. 128), then * the combined alpha that will be used during drawing will be 37.5% (i.e. * 96). */ @Override public void setAlpha(int alpha) { mShapeState.mAlpha = alpha; invalidateSelf(); } @Override public int getAlpha() { return mShapeState.mAlpha; } @Override public void setTintList(ColorStateList tint) { mShapeState.mTint = tint; mTintFilter = updateTintFilter(mTintFilter, tint, mShapeState.mTintMode); invalidateSelf(); } @Override public void setTintMode(PorterDuff.Mode tintMode) { mShapeState.mTintMode = tintMode; mTintFilter = updateTintFilter(mTintFilter, mShapeState.mTint, tintMode); invalidateSelf(); } @Override public void setColorFilter(ColorFilter colorFilter) { mShapeState.mPaint.setColorFilter(colorFilter); invalidateSelf(); } /** * @hide */ @Override @TestApi public void setXfermode(@Nullable Xfermode mode) { mShapeState.mPaint.setXfermode(mode); invalidateSelf(); } @Override public int getOpacity() { if (mShapeState.mShape == null) { final Paint p = mShapeState.mPaint; if (p.getXfermode() == null) { final int alpha = p.getAlpha(); if (alpha == 0) { return PixelFormat.TRANSPARENT; } if (alpha == 255) { return PixelFormat.OPAQUE; } } } // not sure, so be safe return PixelFormat.TRANSLUCENT; } @Override public void setDither(boolean dither) { mShapeState.mPaint.setDither(dither); invalidateSelf(); } @Override protected void onBoundsChange(Rect bounds) { super.onBoundsChange(bounds); updateShape(); } @Override protected boolean onStateChange(int[] stateSet) { final ShapeState state = mShapeState; if (state.mTint != null && state.mTintMode != null) { mTintFilter = updateTintFilter(mTintFilter, state.mTint, state.mTintMode); return true; } return false; } @Override public boolean isStateful() { final ShapeState s = mShapeState; return super.isStateful() || (s.mTint != null && s.mTint.isStateful()); } /** @hide */ @Override public boolean hasFocusStateSpecified() { return mShapeState.mTint != null && mShapeState.mTint.hasFocusStateSpecified(); } /** * Subclasses override this to parse custom subelements. If you handle it, * return true, else return <em>super.inflateTag(...)</em>. */ protected boolean inflateTag(String name, Resources r, XmlPullParser parser, AttributeSet attrs) { if ("padding".equals(name)) { TypedArray a = r.obtainAttributes(attrs, com.android.internal.R.styleable.ShapeDrawablePadding); setPadding(a.getDimensionPixelOffset(com.android.internal.R.styleable.ShapeDrawablePadding_left, 0), a.getDimensionPixelOffset(com.android.internal.R.styleable.ShapeDrawablePadding_top, 0), a.getDimensionPixelOffset(com.android.internal.R.styleable.ShapeDrawablePadding_right, 0), a.getDimensionPixelOffset(com.android.internal.R.styleable.ShapeDrawablePadding_bottom, 0)); a.recycle(); return true; } return false; } @Override public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs, Theme theme) throws XmlPullParserException, IOException { super.inflate(r, parser, attrs, theme); final TypedArray a = obtainAttributes(r, theme, attrs, R.styleable.ShapeDrawable); updateStateFromTypedArray(a); a.recycle(); int type; final int outerDepth = parser.getDepth(); while ((type = parser.next()) != XmlPullParser.END_DOCUMENT && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) { if (type != XmlPullParser.START_TAG) { continue; } final String name = parser.getName(); // call our subclass if (!inflateTag(name, r, parser, attrs)) { android.util.Log.w("drawable", "Unknown element: " + name + " for ShapeDrawable " + this); } } // Update local properties. updateLocalState(); } @Override public void applyTheme(Theme t) { super.applyTheme(t); final ShapeState state = mShapeState; if (state == null) { return; } if (state.mThemeAttrs != null) { final TypedArray a = t.resolveAttributes(state.mThemeAttrs, R.styleable.ShapeDrawable); updateStateFromTypedArray(a); a.recycle(); } // Apply theme to contained color state list. if (state.mTint != null && state.mTint.canApplyTheme()) { state.mTint = state.mTint.obtainForTheme(t); } // Update local properties. updateLocalState(); } private void updateStateFromTypedArray(TypedArray a) { final ShapeState state = mShapeState; final Paint paint = state.mPaint; // Account for any configuration changes. state.mChangingConfigurations |= a.getChangingConfigurations(); // Extract the theme attributes, if any. state.mThemeAttrs = a.extractThemeAttrs(); int color = paint.getColor(); color = a.getColor(R.styleable.ShapeDrawable_color, color); paint.setColor(color); boolean dither = paint.isDither(); dither = a.getBoolean(R.styleable.ShapeDrawable_dither, dither); paint.setDither(dither); state.mIntrinsicWidth = (int) a.getDimension(R.styleable.ShapeDrawable_width, state.mIntrinsicWidth); state.mIntrinsicHeight = (int) a.getDimension(R.styleable.ShapeDrawable_height, state.mIntrinsicHeight); final int tintMode = a.getInt(R.styleable.ShapeDrawable_tintMode, -1); if (tintMode != -1) { state.mTintMode = Drawable.parseTintMode(tintMode, Mode.SRC_IN); } final ColorStateList tint = a.getColorStateList(R.styleable.ShapeDrawable_tint); if (tint != null) { state.mTint = tint; } } private void updateShape() { if (mShapeState.mShape != null) { final Rect r = getBounds(); final int w = r.width(); final int h = r.height(); mShapeState.mShape.resize(w, h); if (mShapeState.mShaderFactory != null) { mShapeState.mPaint.setShader(mShapeState.mShaderFactory.resize(w, h)); } } invalidateSelf(); } @Override public void getOutline(Outline outline) { if (mShapeState.mShape != null) { mShapeState.mShape.getOutline(outline); outline.setAlpha(getAlpha() / 255.0f); } } @Override public ConstantState getConstantState() { mShapeState.mChangingConfigurations = getChangingConfigurations(); return mShapeState; } @Override public Drawable mutate() { if (!mMutated && super.mutate() == this) { mShapeState = new ShapeState(mShapeState); updateLocalState(); mMutated = true; } return this; } /** * @hide */ public void clearMutated() { super.clearMutated(); mMutated = false; } /** * Defines the intrinsic properties of this ShapeDrawable's Shape. */ static final class ShapeState extends ConstantState { final @NonNull Paint mPaint; @Config int mChangingConfigurations; int[] mThemeAttrs; Shape mShape; ColorStateList mTint; Mode mTintMode = DEFAULT_TINT_MODE; Rect mPadding; int mIntrinsicWidth; int mIntrinsicHeight; int mAlpha = 255; ShaderFactory mShaderFactory; /** * Constructs a new ShapeState. */ ShapeState() { mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); } /** * Constructs a new ShapeState that contains a deep copy of the * specified ShapeState. * * @param orig the state to create a deep copy of */ ShapeState(@NonNull ShapeState orig) { mChangingConfigurations = orig.mChangingConfigurations; mPaint = new Paint(orig.mPaint); mThemeAttrs = orig.mThemeAttrs; if (orig.mShape != null) { try { mShape = orig.mShape.clone(); } catch (CloneNotSupportedException e) { // Well, at least we tried. mShape = orig.mShape; } } mTint = orig.mTint; mTintMode = orig.mTintMode; if (orig.mPadding != null) { mPadding = new Rect(orig.mPadding); } mIntrinsicWidth = orig.mIntrinsicWidth; mIntrinsicHeight = orig.mIntrinsicHeight; mAlpha = orig.mAlpha; // We don't have any way to clone a shader factory, so hopefully // this class doesn't contain any local state. mShaderFactory = orig.mShaderFactory; } @Override public boolean canApplyTheme() { return mThemeAttrs != null || (mTint != null && mTint.canApplyTheme()); } @Override public Drawable newDrawable() { return new ShapeDrawable(this, null); } @Override public Drawable newDrawable(Resources res) { return new ShapeDrawable(this, res); } @Override public @Config int getChangingConfigurations() { return mChangingConfigurations | (mTint != null ? mTint.getChangingConfigurations() : 0); } } /** * The one constructor to rule them all. This is called by all public * constructors to set the state and initialize local properties. */ private ShapeDrawable(ShapeState state, Resources res) { mShapeState = state; updateLocalState(); } /** * Initializes local dynamic properties from state. This should be called * after significant state changes, e.g. from the One True Constructor and * after inflating or applying a theme. */ private void updateLocalState() { mTintFilter = updateTintFilter(mTintFilter, mShapeState.mTint, mShapeState.mTintMode); } /** * Base class defines a factory object that is called each time the drawable * is resized (has a new width or height). Its resize() method returns a * corresponding shader, or null. Implement this class if you'd like your * ShapeDrawable to use a special {@link android.graphics.Shader}, such as a * {@link android.graphics.LinearGradient}. */ public static abstract class ShaderFactory { /** * Returns the Shader to be drawn when a Drawable is drawn. The * dimensions of the Drawable are passed because they may be needed to * adjust how the Shader is configured for drawing. This is called by * ShapeDrawable.setShape(). * * @param width the width of the Drawable being drawn * @param height the heigh of the Drawable being drawn * @return the Shader to be drawn */ public abstract Shader resize(int width, int height); } }