Android Canvas Wiederherstellen und Rückgängigmachen
Ich arbeite im Zeichnen von project.my Code klug arbeiten, aber Canvas Redo und Undo-Operation funktioniert nicht perfekt. Undo-Operation funktioniert nicht perfekt und Redo-Operationen funktioniert nicht perfekt Operation entferne das letzte Element von undopaths arraylist und speichere es in path arraylist.
Hier ist mein Code:
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
public class DrawView extends View implements OnTouchListener {
private Canvas mCanvas;
private Path mPath;
private Paint mPaint;
private ArrayList<Path> paths = new ArrayList<Path>();
private ArrayList<Path> undonePaths = new ArrayList<Path>();
private Bitmap im;
public DrawView(Context context)
{
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
this.setOnTouchListener(this);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFFFFFFFF);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(6);
mCanvas = new Canvas();
mPath = new Path();
paths.add(mPath);
im=BitmapFactory.decodeResource(context.getResources(),R.drawable.ic_launcher);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
@Override
protected void onDraw(Canvas canvas) {
//mPath = new Path();
//canvas.drawPath(mPath, mPaint);
for (Path p : paths){
canvas.drawPath(p, mPaint);
}
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
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 = new Path();
paths.add(mPath);
}
public void onClickUndo () {
if (paths.size()>0)
{
undonePaths.add(paths.remove(paths.size()-1));
invalidate();
}
else
{
}
//toast the user
}
public void onClickRedo (){
if (undonePaths.size()>0)
{
paths.add(undonePaths.remove(undonePaths.size()-1));
invalidate();
}
else
{
}
//toast the user
}
@Override
public boolean onTouch(View arg0, MotionEvent event) {
float x = event.getX();
float 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;
}
}
Diese Code-Zeichnung funktioniert einwandfrei und funktioniert nicht einwandfrei. Vorgang rückgängig machen und wiederholen.
Was ist los mit meinem Code?
Wie man dieses Problem löst, kann mir jeder helfen, der es sehr schätzt.
Hier ist mein Quellcode
http://www.4shared.com/rar/8PQQEZdH/test_draw.html
Vielen Dank...
AKTUALISIERTE:Endlich war mein Problem gelöst. Hier ist meine Zeichenklasse:
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
public class DrawView extends View implements OnTouchListener {
private Canvas mCanvas;
private Path mPath;
private Paint mPaint;
private ArrayList<Path> paths = new ArrayList<Path>();
private ArrayList<Path> undonePaths = new ArrayList<Path>();
private Bitmap im;
public DrawView(Context context)
{
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
this.setOnTouchListener(this);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFFFFFFFF);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(6);
mCanvas = new Canvas();
mPath = new Path();
im=BitmapFactory.decodeResource(context.getResources(),R.drawable.ic_launcher);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
@Override
protected void onDraw(Canvas canvas) {
//mPath = new Path();
//canvas.drawPath(mPath, mPaint);
for (Path p : paths){
canvas.drawPath(p, mPaint);
}
canvas.drawPath(mPath, mPaint);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
undonePaths.clear();
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
paths.add(mPath);
mPath = new Path();
}
public void onClickUndo () {
if (paths.size()>0)
{
undonePaths.add(paths.remove(paths.size()-1));
invalidate();
}
else
{
}
//toast the user
}
public void onClickRedo (){
if (undonePaths.size()>0)
{
paths.add(undonePaths.remove(undonePaths.size()-1));
invalidate();
}
else
{
}
//toast the user
}
@Override
public boolean onTouch(View arg0, MotionEvent event) {
float x = event.getX();
float 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;
}
}
Dieser Code funktioniert perfekt ...!