上一篇文章提及了通过调用系统相册或拍照来实现图片的缩放\裁剪。不过这对于笔者项目的
要求同样不适合,笔者需要的是通过对手机屏幕整个进行一个截图,并对这个截图进行裁剪操作。
依靠系统功能确实可以实现图片的裁剪,但是不够灵活。这里笔者提供一种较为灵活的做法。
但是这种做法的用户体验没有上篇文章的好,至于使用何种方法,读者应该自己衡量。
同样,我们先看实际效果图。
这里展示的是笔者项目的一小部分(阅读器):
我们点击左下角的剪切按钮
我们通过红色边框的四个角来控制裁剪的大小,移动红色框体来控制裁剪的位置区域。
接下来我们看看源码的实现:
首先点击剪切按钮的时候,我们应该生成一个Bitmap对象,传递给另一个Activty处理
具体做法如下:
- cutP.setOnClickListener(new View.OnClickListener() {
- public void onClick(View v) {
- //将一些按钮隐藏
- cutP.setVisibility(View.INVISIBLE);
- mTopBarSwitcher.setVisibility(View.INVISIBLE);
- mPageSlider.setVisibility(View.INVISIBLE);
- back.setVisibility(View.INVISIBLE);
- mPageNumberView.setVisibility(View.INVISIBLE);
- View view = MuPDFActivity.this.getWindow().getDecorView();
- if (false == view.isDrawingCacheEnabled()) {
- view.setDrawingCacheEnabled(true);
- }
- Bitmap bitmap = view.getDrawingCache();
- ImageView imgv = new ImageView(MuPDFActivity.this);
- imgv.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,
- LayoutParams.FILL_PARENT-200));
- imgv.setImageBitmap(bitmap);
- backBitmap = bitmap;
- //传递给另一个Activity进行裁剪
- Intent intent = new Intent();
- intent.setClass(MuPDFActivity.this, CutActivity.class);
- startActivity(intent);
- }
- });
在Activity之间进行Bitmap传递呢?这里我们简单的运用java语法特性来完成具体做法如下:
我们在ActvityA中有一个public static Bitmap bitmap对象,当ActivityA跳转到B时,我们直接
通过ActivityA.bitmap来获取这个对象。
之后就是如何进行裁剪的操作了。操作在另一个Activity中进行。XML配置文件信息如下:
- <?xml version="1.0" encoding="utf-8"?>
- <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:layout_width="match_parent"
- android:layout_height="match_parent"
- >
- <com.artifex.mupdf.Crop_Canvas
- android:id="@+id/myCanvas"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent"
- android:background="#313131"
- />
- <Button
- android:id="@+id/cutCancel"
- android:layout_height="wrap_content"
- android:layout_width="wrap_content"
- android:text="取消"
- android:layout_alignParentBottom="true"
- android:layout_alignParentLeft="true"/>
- <Button
- android:id="@+id/cutEnsure"
- android:layout_height="wrap_content"
- android:layout_width="wrap_content"
- android:text="确定"
- android:layout_alignParentBottom="true"
- android:layout_centerInParent="true"/>
- <Button
- android:id="@+id/toPDF"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:text="ToPDF"
- android:layout_alignParentBottom="true"
- android:layout_alignParentRight="true"/>
- </RelativeLayout>
- package com.artifex.mupdf;
- import android.content.Context;
- import android.graphics.Bitmap;
- import android.graphics.Canvas;
- import android.graphics.Color;
- import android.graphics.Matrix;
- import android.graphics.Paint;
- import android.graphics.Rect;
- import android.graphics.RectF;
- import android.graphics.Bitmap.Config;
- import android.graphics.drawable.BitmapDrawable;
- import android.util.AttributeSet;
- import android.view.MotionEvent;
- import android.widget.ImageView;
- public class Crop_Canvas extends ImageView {
- private final static int PRESS_LB = 0;//表示左下角矩形框
- private final static int PRESS_LT = 1;//表示左上角矩形框
- private final static int PRESS_RB = 2;//表示右下角矩形框
- private final static int PRESS_RT = 3;//表示右上角矩形框
- private Bitmap bitMap = null; //原始图片
- private RectF src = null; //经过比例转换后的裁剪区域
- private RectF dst = null; //图片显示区域,也就是drawBitmap函数中的目标dst
- private RectF ChooseArea = null; //选择区域
- private Paint mPaint = null; //画笔
- private Matrix matrix = null; //矩阵
- private int mx = 0; //存储触笔移动时,之前�?��的触笔的x坐标
- private int my = 0; //存储触笔移动时,之前�?��的触笔的y坐标
- private boolean touchFlag = false; //触笔是否在屏幕之�?
- private boolean cutFlag = false; //是否点击了menu上的裁剪按钮
- private int recFlag = -1; //用来存储触笔点击了哪个小矩形框(改变选择区域大小的小矩形框)
- private boolean firstFlag = false;
- private RectF recLT = null; //左上角的小矩形框
- private RectF recRT = null; //右上角的小矩形框
- private RectF recLB = null; //左下角的小矩形框
- private RectF recRB = null; //右下角的小矩形框
- private static final int LEFT_AREA_ALPHA = 50 * 255 / 100;
- private RectF leftRectL = null;
- private RectF leftRectR = null;
- private RectF leftRectT = null;
- private RectF leftRectB = null;
- private Paint leftAreaPaint = null;
- public Crop_Canvas(Context context, AttributeSet attrs) {
- super(context, attrs);
- this.init();
- }
- public Crop_Canvas(Context context) {
- super(context);
- this.init();
- }
- public void init(){
- cutFlag = true;
- recLT = new RectF();
- recLB = new RectF();
- recRT = new RectF();
- recRB = new RectF();
- dst = new RectF();
- mPaint = new Paint();
- mPaint.setColor(Color.RED);
- mPaint.setStyle(Paint.Style.STROKE); //将画笔的风格改为空心
- ChooseArea = new RectF();
- this.setPressRecLoc();
- src = null;
- firstFlag = true;
- //选择框之外的灰色区域,分成四个矩形框
- leftAreaPaint = new Paint();
- leftAreaPaint.setStyle(Paint.Style.FILL);
- leftAreaPaint.setAlpha(Crop_Canvas.LEFT_AREA_ALPHA);
- }
- public void setBitmap(Bitmap bitmap){
- BitmapDrawable bd = new BitmapDrawable(bitmap);
- src = new RectF(0,0,bd.getIntrinsicWidth(),bd.getIntrinsicHeight());
- this.bitMap = bitmap.copy(Config.ARGB_8888, true);
- this.setImageBitmap(bitMap);
- leftRectB = new RectF();
- leftRectL = new RectF();
- leftRectR = new RectF();
- leftRectT = new RectF();
- }
- public void imageScale(){
- matrix = this.getImageMatrix();
- matrix.mapRect(dst, src);
- int padding = this.getPaddingBottom();
- int width = bitMap.getWidth();
- int height = bitMap.getHeight();
- //dst.set(dst.left+padding,dst.top+padding,dst.right+padding,dst.bottom+padding);
- dst.set(dst.left+20,dst.top+20,width-20,height - 40);
- ChooseArea = new RectF(dst);
- this.setPressRecLoc();
- }
- public Bitmap getSubsetBitmap(){
- float ratioWidth = bitMap.getWidth()/(float)(dst.right-dst.left);
- float ratioHeight = bitMap.getHeight()/(float)(dst.bottom - dst.top);
- int left = (int)((ChooseArea.left - dst.left) * ratioWidth);
- int right = (int)(left + (ChooseArea.right - ChooseArea.left) * ratioWidth);
- int top = (int)((ChooseArea.top - dst.top) * ratioHeight);
- int bottom = (int)(top + (ChooseArea.bottom - ChooseArea.top) * ratioHeight);
- src = new RectF(left,top,right,bottom);
- firstFlag = true;
- set_LeftArea_Alpha();
- return Bitmap.createBitmap(bitMap, left, top, right-left, bottom-top);
- }
- //获得ChooseArea对象
- public RectF getChooseArea(){
- return ChooseArea;
- }
- public void moveChooseArea(int move_x,int move_y){
- if(ChooseArea.left + move_x >= dst.left && ChooseArea.right + move_x <= dst.right
- && ChooseArea.top + move_y >= dst.top && ChooseArea.bottom + move_y <= dst.bottom){
- ChooseArea.set(ChooseArea.left + move_x,ChooseArea.top+move_y
- ,ChooseArea.right + move_x,ChooseArea.bottom+move_y);
- }else{
- if(ChooseArea.left + move_x < dst.left){
- ChooseArea.set(dst.left,ChooseArea.top
- ,ChooseArea.right+dst.left-ChooseArea.left,ChooseArea.bottom);
- }
- if(ChooseArea.right + move_x > dst.right){
- ChooseArea.set(ChooseArea.left+dst.right-ChooseArea.right,ChooseArea.top
- ,dst.right,ChooseArea.bottom);
- }
- if(ChooseArea.top + move_y < dst.top){
- ChooseArea.set(ChooseArea.left,dst.top
- ,ChooseArea.right,ChooseArea.bottom+dst.top-ChooseArea.top);
- }
- if(ChooseArea.bottom + move_y > dst.bottom){
- ChooseArea.set(ChooseArea.left,ChooseArea.top+dst.bottom-ChooseArea.bottom
- ,ChooseArea.right,dst.bottom);
- }
- }
- this.setPressRecLoc();
- mPaint.setColor(Color.GREEN);
- this.invalidate();
- }
- public boolean onTouchEvent(MotionEvent event){
- mPaint.setColor(Color.RED);
- if(event.getAction() == MotionEvent.ACTION_DOWN && cutFlag){
- //System.out.println(event.getX() + "," + event.getY());
- mx = (int)event.getX();
- my = (int)event.getY();
- if(this.judgeLocation(mx,my)){
- touchFlag = true;
- mPaint.setColor(Color.GREEN);
- this.invalidate();
- return true;
- }else{
- if(this.findPresseddst((int)event.getX(), (int)event.getY())){
- touchFlag = true;
- mPaint.setColor(Color.RED);
- return true;
- }
- }
- }
- if(event.getAction() == MotionEvent.ACTION_MOVE && touchFlag){
- //判断是否点击了哪个个小矩形框
- if(this.isOutOfArea((int)event.getX(), (int)event.getY())){
- return true;
- }
- //如果选择区域大小跟图像大小一样时,就不能移动
- if(ChooseArea.left == dst.left && ChooseArea.top == dst.top &&
- ChooseArea.right == dst.right && ChooseArea.bottom == dst.bottom){
- }else{
- this.moveChooseArea((int)event.getX() - mx, (int)event.getY() - my);
- mx = (int)event.getX();
- my = (int)event.getY();
- }
- }
- if(event.getAction() == MotionEvent.ACTION_UP){
- recFlag = -1;
- this.invalidate();
- touchFlag = false;
- }
- return super.onTouchEvent(event);
- }
- private boolean isOutOfArea(int x,int y){
- switch(recFlag){
- case Crop_Canvas.PRESS_LB:
- this.pressLB(x - mx, y - my);
- break;
- case Crop_Canvas.PRESS_LT:
- this.pressLT(x - mx, y - my);
- break;
- case Crop_Canvas.PRESS_RB:
- this.pressRB(x - mx, y - my);
- break;
- case Crop_Canvas.PRESS_RT:
- this.pressRT(x - mx, y - my);
- break;
- default:return false;
- }
- mx = x;
- my = y;
- this.invalidate();
- return true;
- }
- public boolean findPresseddst(int x,int y){
- boolean returnFlag = false;
- if(this.isInRect(x, y, recLB)){
- recFlag = Crop_Canvas.PRESS_LB;
- returnFlag = true;
- }else if(this.isInRect(x, y, recLT)){
- recFlag = Crop_Canvas.PRESS_LT;
- returnFlag = true;
- }else if(this.isInRect(x, y, recRB)){
- recFlag = Crop_Canvas.PRESS_RB;
- returnFlag = true;
- }else if(this.isInRect(x, y, recRT)){
- recFlag = Crop_Canvas.PRESS_RT;
- returnFlag = true;
- }
- return returnFlag;
- }
- public boolean isInRect(int x,int y,RectF rect){
- if(x >= rect.left -20 && x <= rect.right + 20 && y > rect.top - 20 && y < rect.bottom + 20){
- return true;
- }
- return false;
- }
- private void pressLB(int x,int y){
- float left = ChooseArea.left + x;
- float right = ChooseArea.right;
- float top = ChooseArea.top;
- float bottom = ChooseArea.bottom + y;
- if(left <= right - 30 && left >= dst.left && bottom <= dst.bottom && bottom >= top + 30){
- ChooseArea.set(left,top,right,bottom);
- }else{
- if(left + x < dst.left){
- left = dst.left;
- }
- if(bottom + y > dst.bottom){
- bottom = dst.bottom;
- }
- if(ChooseArea.left + x > ChooseArea.right - 30){
- left = ChooseArea.right - 30;
- }
- if(ChooseArea.bottom + y < ChooseArea.top + 30){
- bottom = ChooseArea.top + 30;
- }
- ChooseArea.set(left,top,right,bottom);
- }
- this.setPressRecLoc();
- }
- private void pressLT(int x,int y){
- float left = ChooseArea.left + x;
- float right = ChooseArea.right;
- float top = ChooseArea.top + y;
- float bottom = ChooseArea.bottom;
- if(left <= right - 30 && left >= dst.left && top <= bottom - 30 && top >= dst.top){
- ChooseArea.set(left,top,right,bottom);
- }else{
- if(left < dst.left){
- left = dst.left;
- }
- if(top < dst.top){
- top = dst.top;
- }
- if(left > right - 30){
- left = right - 30;
- }
- if(top > bottom - 30){
- top = bottom - 30;
- }
- ChooseArea.set(left,top,right,bottom);
- }
- this.setPressRecLoc();
- }
- private void pressRT(int x,int y){
- float left = ChooseArea.left;
- float right = ChooseArea.right + x;
- float top = ChooseArea.top + y;
- float bottom = ChooseArea.bottom;
- if(right <= dst.right && right >= left + 30 && top <= bottom - 30 && top >= dst.top){
- ChooseArea.set(left,top,right,bottom);
- }else{
- if(right > dst.right){
- right = dst.right;
- }
- if(top < dst.top){
- top = dst.top;
- }
- if(right < left + 30){
- right = left + 30;
- }
- if(top > bottom - 30){
- top = bottom - 30;
- }
- ChooseArea.set(left,top,right,bottom);
- }
- this.setPressRecLoc();
- }
- private void pressRB(int x,int y){
- float left = ChooseArea.left;
- float right = ChooseArea.right + x;
- float top = ChooseArea.top;
- float bottom = ChooseArea.bottom + y;
- if(right<= dst.right && right >= left + 30 && bottom <= dst.bottom && bottom >= top + 30){
- ChooseArea.set(left,top,right,bottom);
- }else{
- if(right > dst.right){
- right = dst.right;
- }
- if(bottom > dst.bottom){
- bottom = dst.bottom;
- }
- if(right < left + 30){
- right = left + 30;
- }
- if(bottom < top + 30){
- bottom = top + 30;
- }
- ChooseArea.set(left,top,right,bottom);
- }
- this.setPressRecLoc();
- }
- //每次改变选择区域矩形的大小或者移动,各角落上的小矩形也要改变它的Location
- private void setPressRecLoc(){
- recLT.set(ChooseArea.left-5,ChooseArea.top-5 , ChooseArea.left+5, ChooseArea.top+5);
- recLB.set(ChooseArea.left-5,ChooseArea.bottom-5 , ChooseArea.left+5, ChooseArea.bottom+5);
- recRT.set(ChooseArea.right-5,ChooseArea.top-5 , ChooseArea.right+5, ChooseArea.top+5);
- recRB.set(ChooseArea.right-5,ChooseArea.bottom-5 , ChooseArea.right+5, ChooseArea.bottom+5);
- }
- public boolean judgeLocation(float x,float y){
- float start_x = this.getChooseArea().left;
- float start_y = this.getChooseArea().top;
- float last_x = this.getChooseArea().right;
- float last_y = this.getChooseArea().bottom;
- //System.out.println("chubi:" + x + "," + y);
- //System.out.println(start_y + "," + last_y);
- if(x > start_x+10 && x < last_x-10 && y > start_y+10 && y < last_y-10){
- return true;
- }
- return false;
- }
- public void onDraw(Canvas canvas){
- super.onDraw(canvas);
- if(firstFlag){
- this.imageScale();
- firstFlag = false;
- mPaint.setColor(Color.RED);
- System.out.println("Width: " + (dst.right - dst.left));
- System.out.println("Height: " + (dst.bottom - dst.top));
- System.out.println("Width: " + this.getDrawable().getIntrinsicWidth());
- System.out.println("Height: " + this.getDrawable().getIntrinsicHeight());
- }else{
- set_LeftArea_Alpha();
- }
- canvas.drawRect(ChooseArea, mPaint);
- mPaint.setColor(Color.BLUE);
- canvas.drawRect(recLT, mPaint);
- canvas.drawRect(recLB, mPaint);
- canvas.drawRect(recRT, mPaint);
- canvas.drawRect(recRB, mPaint);
- canvas.drawRect(leftRectL, leftAreaPaint);
- canvas.drawRect(leftRectR, leftAreaPaint);
- canvas.drawRect(leftRectT, leftAreaPaint);
- canvas.drawRect(leftRectB, leftAreaPaint);
- }
- public void set_LeftArea_Alpha(){
- leftRectL.set(dst.left, dst.top, ChooseArea.left, dst.bottom);
- leftRectR.set(ChooseArea.right,dst.top,dst.right,dst.bottom);
- leftRectT.set(ChooseArea.left, dst.top, ChooseArea.right, ChooseArea.top);
- leftRectB.set(ChooseArea.left,ChooseArea.bottom,ChooseArea.right,dst.bottom);
- }
- }
- package com.artifex.mupdf.cut;
- import java.io.File;
- import java.io.FileNotFoundException;
- import java.io.FileOutputStream;
- import java.io.IOException;
- import java.util.ArrayList;
- import android.app.Activity;
- import android.graphics.Bitmap;
- import android.os.Bundle;
- import android.view.View;
- import android.view.View.OnClickListener;
- import android.view.Window;
- import android.widget.Button;
- import com.andorid.shu.love.R;
- import com.artifex.mupdf.Crop_Canvas;
- import com.artifex.mupdf.MuPDFActivity;
- public class CutActivity extends Activity {
- private Crop_Canvas canvas = null;
- private Bitmap backBitmap;
- private Button cancel;
- private Button ensure;
- private Button toPDF;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- requestWindowFeature(Window.FEATURE_NO_TITLE);
- setContentView(R.layout.cut_image);
- backBitmap = MuPDFActivity.backBitmap;
- init();
- cancel = (Button) findViewById(R.id.cutCancel);
- cancel.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- CutActivity.this.finish();
- }
- });
- ensure = (Button) findViewById(R.id.cutEnsure);
- ensure.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- //图片保存的路径,之后将之转换为PDF,并以附件的形似发送邮件
- File tmp = new File("/sdcard/lovereader/pic");
- tmp.mkdirs();
- File f = new File("/sdcard/lovereader/pic/" + "testpic" + ".png");
- try {
- f.createNewFile();
- } catch (IOException e1) {
- // TODO Auto-generated catch block
- e1.printStackTrace();
- }
- FileOutputStream fOut = null;
- try {
- fOut = new FileOutputStream(f);
- } catch (FileNotFoundException e) {
- e.printStackTrace();
- }
- canvas.getSubsetBitmap().compress(Bitmap.CompressFormat.PNG, 100, fOut);
- try {
- fOut.flush();
- } catch (IOException e) {
- e.printStackTrace();
- }
- try {
- fOut.close();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- });
- toPDF = (Button)findViewById(R.id.toPDF);
- toPDF.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- // TODO Auto-generated method stub
- ArrayList<String> imageUrllist = new ArrayList<String>();
- imageUrllist.add("/sdcard/lovereader/pic/" + "testpic" + ".png");
- String pdfUrl = "/sdcard/lovereader/tmp/Foreverlove.pdf";
- File tmp = new File("/sdcard/lovereader/tmp");
- tmp.mkdirs();
- File file = PdfManager.Pdf(imageUrllist, pdfUrl);
- try {
- file.createNewFile();
- } catch (IOException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
- }
- });
- }
- private void init() {
- canvas = (Crop_Canvas) findViewById(R.id.myCanvas);
- Bitmap bitmap = backBitmap;
- canvas.setBitmap(bitmap);
- }
- }