Create a bitmap with a circle
/* * 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 app.test; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapShader; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Matrix; import android.graphics.Paint; import android.graphics.Picture; import android.graphics.PorterDuff; import android.graphics.PorterDuffXfermode; import android.graphics.Rect; import android.graphics.RectF; import android.graphics.Shader; import android.graphics.Xfermode; import android.graphics.drawable.Drawable; import android.os.Bundle; import android.util.AttributeSet; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; public class Xfermodes extends GraphicsActivity { // create a bitmap with a circle, used for the "dst" image static Bitmap makeDst(int w, int h) { Bitmap bm = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); Canvas c = new Canvas(bm); Paint p = new Paint(Paint.ANTI_ALIAS_FLAG); p.setColor(0xFFFFCC44); c.drawOval(new RectF(0, 0, w * 3 / 4, h * 3 / 4), p); return bm; } // create a bitmap with a rect, used for the "src" image static Bitmap makeSrc(int w, int h) { Bitmap bm = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); Canvas c = new Canvas(bm); Paint p = new Paint(Paint.ANTI_ALIAS_FLAG); p.setColor(0xFF66AAFF); c.drawRect(w / 3, h / 3, w * 19 / 20, h * 19 / 20, p); return bm; } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(new SampleView(this)); } private static class SampleView extends View { private static final int W = 64; private static final int H = 64; private static final int ROW_MAX = 4; // number of samples per row private Bitmap mSrcB; private Bitmap mDstB; private Shader mBG; // background checker-board pattern private static final Xfermode[] sModes = { new PorterDuffXfermode(PorterDuff.Mode.CLEAR), new PorterDuffXfermode(PorterDuff.Mode.SRC), new PorterDuffXfermode(PorterDuff.Mode.DST), new PorterDuffXfermode(PorterDuff.Mode.SRC_OVER), new PorterDuffXfermode(PorterDuff.Mode.DST_OVER), new PorterDuffXfermode(PorterDuff.Mode.SRC_IN), new PorterDuffXfermode(PorterDuff.Mode.DST_IN), new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT), new PorterDuffXfermode(PorterDuff.Mode.DST_OUT), new PorterDuffXfermode(PorterDuff.Mode.SRC_ATOP), new PorterDuffXfermode(PorterDuff.Mode.DST_ATOP), new PorterDuffXfermode(PorterDuff.Mode.XOR), new PorterDuffXfermode(PorterDuff.Mode.DARKEN), new PorterDuffXfermode(PorterDuff.Mode.LIGHTEN), new PorterDuffXfermode(PorterDuff.Mode.MULTIPLY), new PorterDuffXfermode(PorterDuff.Mode.SCREEN) }; private static final String[] sLabels = { "Clear", "Src", "Dst", "SrcOver", "DstOver", "SrcIn", "DstIn", "SrcOut", "DstOut", "SrcATop", "DstATop", "Xor", "Darken", "Lighten", "Multiply", "Screen" }; public SampleView(Context context) { super(context); mSrcB = makeSrc(W, H); mDstB = makeDst(W, H); // make a ckeckerboard pattern Bitmap bm = Bitmap.createBitmap(new int[] { 0xFFFFFFFF, 0xFFCCCCCC, 0xFFCCCCCC, 0xFFFFFFFF }, 2, 2, Bitmap.Config.RGB_565); mBG = new BitmapShader(bm, Shader.TileMode.REPEAT, Shader.TileMode.REPEAT); Matrix m = new Matrix(); m.setScale(6, 6); mBG.setLocalMatrix(m); } @Override protected void onDraw(Canvas canvas) { canvas.drawColor(Color.WHITE); Paint labelP = new Paint(Paint.ANTI_ALIAS_FLAG); labelP.setTextAlign(Paint.Align.CENTER); Paint paint = new Paint(); paint.setFilterBitmap(false); canvas.translate(15, 35); int x = 0; int y = 0; for (int i = 0; i < sModes.length; i++) { // draw the border paint.setStyle(Paint.Style.STROKE); paint.setShader(null); canvas.drawRect(x - 0.5f, y - 0.5f, x + W + 0.5f, y + H + 0.5f, paint); // draw the checker-board pattern paint.setStyle(Paint.Style.FILL); paint.setShader(mBG); canvas.drawRect(x, y, x + W, y + H, paint); // draw the src/dst example into our offscreen bitmap int sc = canvas.saveLayer(x, y, x + W, y + H, null, Canvas.MATRIX_SAVE_FLAG | Canvas.CLIP_SAVE_FLAG | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG | Canvas.FULL_COLOR_LAYER_SAVE_FLAG | Canvas.CLIP_TO_LAYER_SAVE_FLAG); canvas.translate(x, y); canvas.drawBitmap(mDstB, 0, 0, paint); paint.setXfermode(sModes[i]); canvas.drawBitmap(mSrcB, 0, 0, paint); paint.setXfermode(null); canvas.restoreToCount(sc); // draw the label canvas.drawText(sLabels[i], x + W / 2, y - labelP.getTextSize() / 2, labelP); x += W + 10; // wrap around when we've drawn enough for one row if ((i % ROW_MAX) == ROW_MAX - 1) { x = 0; y += H + 30; } } } } } class GraphicsActivity extends Activity { // set to true to test Picture private static final boolean TEST_PICTURE = false; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); } @Override public void setContentView(View view) { if (TEST_PICTURE) { ViewGroup vg = new PictureLayout(this); vg.addView(view); view = vg; } super.setContentView(view); } } class PictureLayout extends ViewGroup { private final Picture mPicture = new Picture(); public PictureLayout(Context context) { super(context); } public PictureLayout(Context context, AttributeSet attrs) { super(context, attrs); } @Override public void addView(View child) { if (getChildCount() > 1) { throw new IllegalStateException( "PictureLayout can host only one direct child"); } super.addView(child); } @Override public void addView(View child, int index) { if (getChildCount() > 1) { throw new IllegalStateException( "PictureLayout can host only one direct child"); } super.addView(child, index); } @Override public void addView(View child, LayoutParams params) { if (getChildCount() > 1) { throw new IllegalStateException( "PictureLayout can host only one direct child"); } super.addView(child, params); } @Override public void addView(View child, int index, LayoutParams params) { if (getChildCount() > 1) { throw new IllegalStateException( "PictureLayout can host only one direct child"); } super.addView(child, index, params); } @Override protected LayoutParams generateDefaultLayoutParams() { return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { final int count = getChildCount(); int maxHeight = 0; int maxWidth = 0; for (int i = 0; i < count; i++) { final View child = getChildAt(i); if (child.getVisibility() != GONE) { measureChild(child, widthMeasureSpec, heightMeasureSpec); } } maxWidth += getPaddingLeft() + getPaddingRight(); maxHeight += getPaddingTop() + getPaddingBottom(); Drawable drawable = getBackground(); if (drawable != null) { maxHeight = Math.max(maxHeight, drawable.getMinimumHeight()); maxWidth = Math.max(maxWidth, drawable.getMinimumWidth()); } setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec), resolveSize(maxHeight, heightMeasureSpec)); } private void drawPict(Canvas canvas, int x, int y, int w, int h, float sx, float sy) { canvas.save(); canvas.translate(x, y); canvas.clipRect(0, 0, w, h); canvas.scale(0.5f, 0.5f); canvas.scale(sx, sy, w, h); canvas.drawPicture(mPicture); canvas.restore(); } @Override protected void dispatchDraw(Canvas canvas) { super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight())); mPicture.endRecording(); int x = getWidth() / 2; int y = getHeight() / 2; if (false) { canvas.drawPicture(mPicture); } else { drawPict(canvas, 0, 0, x, y, 1, 1); drawPict(canvas, x, 0, x, y, -1, 1); drawPict(canvas, 0, y, x, y, 1, -1); drawPict(canvas, x, y, x, y, -1, -1); } } @Override public ViewParent invalidateChildInParent(int[] location, Rect dirty) { location[0] = getLeft(); location[1] = getTop(); dirty.set(0, 0, getWidth(), getHeight()); return getParent(); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { final int count = super.getChildCount(); for (int i = 0; i < count; i++) { final View child = getChildAt(i); if (child.getVisibility() != GONE) { final int childLeft = getPaddingLeft(); final int childTop = getPaddingTop(); child.layout(childLeft, childTop, childLeft + child.getMeasuredWidth(), childTop + child.getMeasuredHeight()); } } } }