Привет, мне нужно выполнить операцию отмены в красках. Кто-то предлагает использовать шаблон команды, но я не получаю шаблон команды. Там есть какое-то решение. помогите мне как отменить.
Я рисую краски, используя приведенный ниже код.
BookType3.class:
public class BookType3 extends Activity implements OnClickListener{
MyView myview;
int counter=0;
private Paint mBitmapPaint;
TextView t1,t2;
private Bitmap mBitmap;
public static boolean action=false;
Button back,erase,undo,save,home;
int image1,image2,image3;
private Canvas mCanvas;
RelativeLayout relative;
RelativeLayout.LayoutParams lp6,lp7;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.booktype1);
List<String> names = Arrays.asList("a","b","c");
relative=(RelativeLayout)findViewById(R.id.relative3);
myview = new MyView(this);
myview.setId(004);
lp6 = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
myview.setLayoutParams(lp6);
myview.setBackgroundResource(R.drawable.writingsapce);
undo=(Button)findViewById(R.id.undobutton);
undo.setOnClickListener(this);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(4);
String s1="";
t1=(TextView)findViewById(R.id.button1);
t1.setOnClickListener(this);
t2=(TextView)findViewById(R.id.button2);
t2.setOnClickListener(this);
relative.addView(myview,lp6);
}
private Paint mPaint;
public class MyView extends View{
private Path mPath;
public MyView(Context context) {
super(context);
// TODO Auto-generated constructor stub
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
if(action)
{
invalidate();
}
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 2;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int x = (int) event.getX();
int y = (int) event.getY();
Log.i("x",""+event.getX());
Log.i("y",""+event.getY());
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
}
public void onClick(View v) {
// TODO Auto-generated method stub
if(v==t1)
{
mPaint.setColor(Color.RED);
t30.setText("A");
t31.setText("a");
t32.setText("Aa");
t30.setTextColor(Color.RED);
t31.setTextColor(Color.RED);
t32.setTextColor(Color.RED);
try{
mBitmap.eraseColor(android.graphics.Color.TRANSPARENT);
Canvas Canvas=new Canvas(mBitmap);
action=true;
myview.onDraw(Canvas);
}catch(IllegalStateException ie){
ie.printStackTrace();
}
}
if(v==t2)
{
t30.setTextColor(Color.BLUE);
t31.setTextColor(Color.BLUE);
t32.setTextColor(Color.BLUE);
mPaint.setColor(Color.BLUE);
t30.setText("B");
t31.setText("b");
t32.setText("Bb");
try{
mBitmap.eraseColor(android.graphics.Color.TRANSPARENT);
Canvas Canvas=new Canvas(mBitmap);
action=true;
myview.onDraw(Canvas);
}catch(IllegalStateException ie){
ie.printStackTrace();
}
}
if(v==undo)
{
}
}
}