类似美图秀秀 拼图 大致原理

大致原理为：

分割不同的path，然后draw这些即可。

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.Region;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Toast;


public class ShowPathActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(new PathView(this));
}
}


class PathView extends View {
private Context mCtx;
private Path[] mPath;
private Bitmap[] mBmp;
private boolean[] mBmpFlag;
private float[][] mPathLT;
private float[][] mPathOffset;
int mPathNum = 3;
private int border = 6;
private int viewWdh, viewHgt, itemHgt;
public static int PICIDS[] = { R.drawable.showguide1,
R.drawable.showguide2, R.drawable.showguide3,
R.drawable.showguide4, R.drawable.showguide5, R.drawable.showguide6 };


public PathView(Context context) {
super(context);
mCtx = context;


initialView();
initPath();
}


private void initPath() {
// mPathNum = (int) (Math.random() * 10);
mPath = new Path[mPathNum];
for (int i = 0; i < mPathNum; i++) {
mPath[i] = new Path();
}
mBmpFlag = new boolean[mPathNum];

mPathLT = new float[mPathNum][2];
mPathOffset = new float[mPathNum][2];
for (int i = 0; i < mPathNum; i++) {
mBmpFlag[i] = false;
mPathLT[i][0] = 0f;
mPathLT[i][1] = 0f;
mPathOffset[i][0] = 0f;
mPathOffset[i][1] = 0f;
}


for (int i = 0; i < mPathNum; i++) {
mPathLT[i][0] = 0;
mPathLT[i][1] = (itemHgt + border)*i;
mPath[i].moveTo(mPathLT[i][0], mPathLT[i][1]);
mPath[i].lineTo(viewWdh, mPathLT[i][1]);
mPath[i].lineTo(viewWdh, mPathLT[i][1] + itemHgt);
mPath[i].lineTo(0, mPathLT[i][1] + itemHgt);
mPath[i].close();
}


// get bitmap
mBmp = new Bitmap[mPathNum];
for (int i = 0; i < mPathNum; i++) {
BitmapFactory.Options opt = new BitmapFactory.Options();
opt.inJustDecodeBounds = true;
BitmapFactory.decodeResource(getResources(), PICIDS[i], opt);
int bmpWdh = opt.outWidth;
int bmpHgt = opt.outHeight;


int size = caculateSampleSize(bmpWdh, bmpHgt, viewWdh, itemHgt);
opt.inJustDecodeBounds = false;
opt.inSampleSize = size;
mBmp[i] = BitmapFactory.decodeResource(getResources(), PICIDS[i],
opt);
}
}


private int caculateSampleSize(int picWdh, int picHgt, int showWdh,
int showHgt) {
// 如果此时显示区域比图片大，直接返回
if ((showWdh < picWdh) || (showHgt < picHgt)) {
int wdhSample = picWdh / showWdh;
int hgtSample = picHgt / showHgt;
// 利用小的来处理
int sample = wdhSample > hgtSample ? hgtSample : wdhSample;
int minSample = 2;
while (sample > minSample) {
minSample *= 2;
}


return minSample >> 1;
} else {
return 1;
}
}


private void initialView() {
DisplayMetrics display = mCtx.getResources().getDisplayMetrics();
viewWdh = display.widthPixels;
itemHgt = display.heightPixels >> 2;
viewHgt = itemHgt * 3 + 2 * border;
Log.d("screen parameter", "wdh = " + viewWdh + ":hgt = "
+ display.heightPixels);
}


@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
setMeasuredDimension(viewWdh, viewHgt);
}


@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawColor(Color.GRAY);// 显示背景颜色
Paint paint = new Paint();
paint.setColor(Color.GRAY);
canvas.drawPaint(paint);


// draw1(canvas);
draw2(canvas, paint);
}

private void draw1(Canvas canvas){
for (int i = 0; i < mPathNum; i++) {
canvas.save();
canvas.clipPath(mPath[i]);
BitmapDrawable mDrawable = new BitmapDrawable(mBmp[i]);
mDrawable.setBounds(0, (itemHgt + border) * i, viewWdh, (itemHgt + border) * i + itemHgt);
mDrawable.draw(canvas);
canvas.restore();
}
}

private void draw2(Canvas canvas, Paint paint){
for (int i = 0; i < mPathNum; i++) {
canvas.save();
drawScene(canvas, paint, i);
canvas.restore();
}
}

private void drawScene(Canvas canvas, Paint paint, int idx) {  
canvas.clipPath(mPath[idx]);
        canvas.drawColor(Color.GRAY);
        if (mBmpFlag[idx]) {
        canvas.drawBitmap(mBmp[idx], mPathLT[idx][0] + mPathOffsetX + mPathOffset[idx][0], mPathLT[idx][1] + mPathOffsetY + mPathOffset[idx][1], paint);
} else {
        canvas.drawBitmap(mBmp[idx], mPathLT[idx][0] + mPathOffset[idx][0], mPathLT[idx][1] + mPathOffset[idx][1], paint);
}
        
    }

float ptx, pty;
float mPathOffsetX, mPathOffsetY;
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
for (int i = 0; i < mPathNum; i++) {
mBmpFlag[i] = false;
}
ptx = event.getRawX();
pty = event.getRawY();
mPathOffsetX = 0;
mPathOffsetY = 0;

int cflag = 0;
for (cflag = 0; cflag < mPathNum; cflag++) {
if (contains(mPath[cflag], ptx, pty)) {
mBmpFlag[cflag] = true;
break;
}
}
break;
case MotionEvent.ACTION_MOVE:
mPathOffsetX = event.getRawX() - ptx;
mPathOffsetY = event.getRawY() - pty;
invalidate();
break;
case MotionEvent.ACTION_UP:
for (int i = 0; i < mPathNum; i++) {
if (mBmpFlag[i]) {
mPathOffset[i][0] += event.getRawX() - ptx;
mPathOffset[i][1] += event.getRawY() - pty;

if (mPathOffset[i][0] < 0) {
mPathOffset[i][0] = 0;
}
if (mPathOffset[i][0] > (mBmp[i].getWidth() - viewWdh)) {
mPathOffset[i][0] = (mBmp[i].getWidth() - viewWdh);
}
if (mPathOffset[i][1] > 0) {
mPathOffset[i][1] = 0;
}
if (mPathOffset[i][1] < -(mBmp[i].getHeight() - itemHgt)) {
mPathOffset[i][1] = -(mBmp[i].getHeight() - itemHgt);
}
mBmpFlag[i] = false;
break;
}
}
invalidate();
break;
default:
break;
}

return true;
}

private boolean contains(Path paramPath, float pointx, float pointy)
 {
   RectF localRectF = new RectF();
   paramPath.computeBounds(localRectF, true);
   Region localRegion = new Region();
   localRegion.setPath(paramPath, new Region((int)localRectF.left, (int)localRectF.top, (int)localRectF.right, (int)localRectF.bottom));
   return localRegion.contains((int)pointx, (int)pointy);
 }
}