我目前正在使用表面视图进行绘图，但我遇到的问题是没有使用命令模式对曲面视图执行撤消重做操作。如果有人知道它，请帮助。
我的代码是XML ..
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<FrameLayout
android:id="@+id/frameLayout"
android:layout_width="fill_parent"
android:layout_height="430dp"/>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="50dp"
android:gravity="center_horizontal"
android:layout_gravity="bottom"
android:background="#c2300f">
<Button
android:id="@+id/buttonUndo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Undo" />
<Button
android:id="@+id/buttonRedo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Redo" />
<Button
android:id="@+id/buttonColor"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Color" />
</LinearLayout>
</LinearLayout>
主要活动是......
package com.example.surfacetuto;
import android.app.Activity;
import android.graphics.Paint;
import android.graphics.Point;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener{
DrawingSurface ds;
FrameLayout frm;
Button btnU,btnR,btnC;
int color=0xfff00000;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ds=new DrawingSurface(this);
setContentView(R.layout.activity_main);
frm=(FrameLayout)findViewById(R.id.frameLayout);
frm.addView(ds);
btnU=(Button)findViewById(R.id.buttonUndo);
btnR=(Button)findViewById(R.id.buttonRedo);
btnC=(Button)findViewById(R.id.buttonColor);
btnU.setOnClickListener(this);
btnR.setOnClickListener(this);
btnC.setOnClickListener(this);
btnU.setEnabled(true);
btnR.setEnabled(true);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.buttonUndo:
ds.undo();
if( ds.hasMoreUndo() == false ){
btnU.setEnabled( false );
}
btnU.setEnabled( true );
Toast.makeText(getApplicationContext(), "Undo", 0).show();
break;
case R.id.buttonRedo:
ds.redo();
if( ds.hasMoreRedo() == false ){
btnR.setEnabled( false );
}
btnR.setEnabled( true );
Toast.makeText(getApplicationContext(), "Redo", 1).show();
break;
case R.id.buttonColor:
Toast.makeText(getApplicationContext(), "Color", 2).show();
ds.colorNew();
break;
default:
break;
}
}
}
绘制Surface类是.....
package com.example.surfacetuto;
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.Matrix;
import android.graphics.Paint;
import android.graphics.Paint.Cap;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Toast;
public class DrawingSurface extends SurfaceView implements SurfaceHolder.Callback {
Canvas cacheCanvas;
Bitmap backBuffer;
int width, height, clientHeight;
Paint paint;
Context context;
SurfaceHolder mHolder;
protected DrawThread thread;
private Boolean _run;
public boolean isDrawing = true;
private Bitmap mBitmap;
private CommandManager commandManager;
public DrawingSurface(Context context) {
super(context);
this.context = context;
init();
}
public DrawingSurface(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;
init();
}
private void init() {
mHolder = getHolder();
mHolder.addCallback(this);
commandManager = new CommandManager();
thread = new DrawThread(getHolder());
}
class DrawThread extends Thread{
private SurfaceHolder mSurfaceHolder;
public DrawThread(SurfaceHolder surfaceHolder){
mSurfaceHolder = surfaceHolder;
}
public void setRunning(boolean run) {
_run = run;
}
@Override
public void run() {
Canvas canvas = null;
while (_run){
if(isDrawing == true){
try{
canvas = mSurfaceHolder.lockCanvas(null);
if(mBitmap == null){
mBitmap = Bitmap.createBitmap (100, 100, Bitmap.Config.ARGB_8888);
}
final Canvas c = new Canvas (mBitmap);
c.drawColor(Color.WHITE);
canvas.drawColor(Color.WHITE);
commandManager.executeAll(c);
canvas.drawBitmap (mBitmap, 0, 0,null);
} finally {
mSurfaceHolder.unlockCanvasAndPost(canvas);
}
isDrawing = true;
}
}
}
}
public void addDrawingPath (DrawingPath drawingPath){
commandManager.addCommand(drawingPath);
}
int lastX, lastY, currX, currY;
boolean isDeleting;
@Override
public boolean onTouchEvent(MotionEvent event) {
super.onTouchEvent(event);
int action = event.getAction();
switch(action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
lastX = (int) event.getX();
lastY = (int) event.getY();
break;
case MotionEvent.ACTION_MOVE:
if(isDeleting) break;
currX = (int) event.getX();
currY = (int) event.getY();
cacheCanvas.drawLine(lastX, lastY, currX, currY, paint);
lastX = currX;
lastY = currY;
break;
case MotionEvent.ACTION_UP:
if(isDeleting) isDeleting = false;
break;
case MotionEvent.ACTION_POINTER_DOWN:
cacheCanvas.drawColor(Color.WHITE);
isDeleting = true;
break;
case MotionEvent.ACTION_POINTER_UP:
break;
}
draw();
return true;
}
protected void draw() {
if(clientHeight==0) {
clientHeight = getClientHeight();
height = clientHeight;
backBuffer = Bitmap.createBitmap( width, height, Bitmap.Config.ARGB_8888);
cacheCanvas.setBitmap(backBuffer);
cacheCanvas.drawColor(Color.WHITE);
}
Canvas canvas = null;
try{
canvas = mHolder.lockCanvas(null);
canvas.drawBitmap(backBuffer, 0,0, paint);
}catch(Exception ex){
ex.printStackTrace();
}finally{
if(mHolder!=null) mHolder.unlockCanvasAndPost(canvas);
}
}
private int getClientHeight() {
Rect rect= new Rect();
Window window = ((Activity)context).getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rect);
int statusBarHeight= rect.top;
int contentViewTop= window.findViewById(Window.ID_ANDROID_CONTENT).getTop();
int titleBarHeight= contentViewTop - statusBarHeight;
return ((Activity)context).getWindowManager().getDefaultDisplay().
getHeight() - statusBarHeight - titleBarHeight;
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
}
public void surfaceCreated(SurfaceHolder holder) {
thread.setRunning(true);
thread.start();
width = getWidth();
height = getHeight();
cacheCanvas = new Canvas();
backBuffer = Bitmap.createBitmap( width, height, Bitmap.Config.ARGB_8888);
cacheCanvas.setBitmap(backBuffer);
cacheCanvas.drawColor(Color.WHITE);
paint = new Paint();
paint.setColor(Color.BLUE);
paint.setStrokeWidth(10);
paint.setStrokeCap(Paint.Cap.ROUND);
paint.setStrokeJoin(Paint.Join.ROUND);
draw();
}
public void surfaceDestroyed(SurfaceHolder holder) {
boolean retry = true;
thread.setRunning(false);
while (retry) {
try {
thread.join();
retry = false;
} catch (InterruptedException e) {
// we will try it again and again...
}
}
}
public void colorNew() {
// TODO Auto-generated method stub
paint.setColor(Color.GRAY);
}
public void undo() {
// TODO Auto-generated method stub
isDrawing = true;
commandManager.undo();
}
public void redo() {
// TODO Auto-generated method stub
isDrawing = true;
commandManager.redo();
}
public boolean hasMoreUndo() {
// TODO Auto-generated method stub
return commandManager.hasMoreUndo();
}
public boolean hasMoreRedo() {
// TODO Auto-generated method stub
return commandManager.hasMoreRedo();
}
}
答案 0 :(得分：0)