Bitmap Example1 in Android Development
21/08/2012
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This example explains how you can use bitmaps to create funny animations. Algorithm: 1.) Create a new project by File-> New -> Android Project name it BitmapExample1. 2.) Create and write following into GraphicsActivity.java:
package com.example.BitmapExample1;import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.ViewGroup;class GraphicsActivity extends Activity { 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); } }
3.) Write following into PictureLayout.java:
package com.example.BitmapExample1;import android.content.Context; import android.graphics.Canvas; import android.graphics.Picture; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent;public class PictureLayout extends ViewGroup { private final Picture mPicture = new Picture(); public PictureLayou(Conetxt context) { super(context); } public PictureLayout(Context context,  AtributeSet 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( Viewchild, int index) { if (getChildCount() > 1) { throw new  IllagelStateException("PictureLayout can host only one direct child"); } super.addView(child, index); } @Override public void addView(View child, LayoutParams params) { if (getChildCount() > 1) { throw new IllagelStateException("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 IllagelStateException("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()); } } } }
4.) Run for output. Steps: 1.) Create a project named BitmapExample1 and set the information as stated in the image. Build Target: Android 4.0 Application Name: BitmapExample1 Package Name: com. example. BitmapExample1 Activity Name: BitmapExample1 Min SDK Version: 14 2.) Open BitmapExample1.java file and write following code there:
package com.example.BitmapExample1;import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Matrix; import android.os.Bundle; import android.util.FloatMath; import android.view. MotionEvent; import android.view.View;public class BitmapExample1 extends GraphicsActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(new SampleView(this)); } private static class SampleView extends View { private static final int WIDTH = 20; private static final int HEIGHT = 20; private static final int COUNT = (WIDTH + 1) * (HEIGHT + 1); private final Bitmap mBitmap; private final float[] mVerts = new float[COUNT*2]; private final float[] mOrig = new float[COUNT*2]; private final Matrix mMatrix = new Matrix(); private final Matrix mInverse = new Matrix(); private static void setXY(float[] array, int index, float x, float y) { array[index*2 + 0] = x; array[index*2 + 1] = y; } public SampleView(Context context) { super(context); setFocusable(true); mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.baby); float w = mBitmap.getWidth(); float h = mBitmap.getHeight(); // construct our mesh int index = 0; for (int y = 0; y <= HEIGHT; y++) { float fy = h * y / HEIGHT; for (int x = 0; x <= WIDTH; x++) { float fx = w * x / WIDTH; setXY(mVerts, index, fx, fy); setXY(mOrig, index, fx, fy); index += 1; } } mMatrix.setTranslate(10, 10); mMatrix.invert(mInverse); } @Override protected void onDraw(Canvas canvas) { canvas.drawColor(0xFFCCCCCC); canvas.concat(mMatrix); canvas.drawBitmapMesh(mBitmap, WIDTH, HEIGHT, mVerts, 0, null, 0, null); } private void warp(float cx, float cy) { final float K = 10000; float[] src = mOrig; float[] dst = mVerts; for (int i = 0; i < COUNT*2; i += 2) { float x = src[i+0]; float y = src[i+1]; float dx = cx - x; float dy = cy - y; float dd = dx*dx + dy*dy; float d = FloatMath.sqrt(dd); float pull = K / (dd + 0.000001f); pull /= (d + 0.000001f); if (pull >= 1) { dst[i+0] = cx; dst[i+1] = cy; } else { dst[i+0] = x + dx * pull; dst[i+1] = y + dy * pull; } } } private int mLastWarpX = -9999; private int mLastWarpY; @Override public boolean onTouchEvent(MotionEvent event) { float[] pt = { event.getX(), event.getY() }; mInverse.mapPoints(pt); int x = (int)pt[0]; int y = (int)pt[1]; if (mLastWarpX != x