/* * 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 com.example.android.apis.graphics;// Need the following import to get access to the app resources, since this// class is in a sub-package.//import com.example.android.apis.R;import android.app.Activity;import android.content.Context;import android.graphics.*;import android.os.Bundle;import android.view.View;public class PolyToPoly extends GraphicsActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(new SampleView(this));    }        private static class SampleView extends View {        private Paint   mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);        private Matrix  mMatrix = new Matrix();        private Paint.FontMetrics mFontMetrics;        private void doDraw(Canvas canvas, float src[], float dst[]) {            canvas.save();            mMatrix.setPolyToPoly(src, 0, dst, 0, src.length >> 1);            canvas.concat(mMatrix);                        mPaint.setColor(Color.GRAY);            mPaint.setStyle(Paint.Style.STROKE);            canvas.drawRect(0, 0, 64, 64, mPaint);            canvas.drawLine(0, 0, 64, 64, mPaint);            canvas.drawLine(0, 64, 64, 0, mPaint);                        mPaint.setColor(Color.RED);            mPaint.setStyle(Paint.Style.FILL);            // how to draw the text center on our square            // centering in X is easy... use alignment (and X at midpoint)            float x = 64/2;            // centering in Y, we need to measure ascent/descent first            float y = 64/2 - (mFontMetrics.ascent + mFontMetrics.descent)/2;            canvas.drawText(src.length/2 + "", x, y, mPaint);                        canvas.restore();        }        public SampleView(Context context) {            super(context);            // for when the style is STROKE            mPaint.setStrokeWidth(4);            // for when we draw text            mPaint.setTextSize(40);            mPaint.setTextAlign(Paint.Align.CENTER);            mFontMetrics = mPaint.getFontMetrics();        }                @Override protected void onDraw(Canvas canvas) {            Paint paint = mPaint;            canvas.drawColor(Color.WHITE);            canvas.save();            canvas.translate(10, 10);            // translate (1 point)            doDraw(canvas, new float[] { 0, 0 }, new float[] { 5, 5 });            canvas.restore();                        canvas.save();            canvas.translate(160, 10);            // rotate/uniform-scale (2 points)            doDraw(canvas, new float[] { 32, 32, 64, 32 },                           new float[] { 32, 32, 64, 48 });            canvas.restore();            canvas.save();            canvas.translate(10, 110);            // rotate/skew (3 points)            doDraw(canvas, new float[] { 0, 0, 64, 0, 0, 64 },                           new float[] { 0, 0, 96, 0, 24, 64 });            canvas.restore();            canvas.save();            canvas.translate(160, 110);            // perspective (4 points)            doDraw(canvas, new float[] { 0, 0, 64, 0, 64, 64, 0, 64 },                           new float[] { 0, 0, 96, 0, 64, 96, 0, 64 });            canvas.restore();        }    }}