onTouchevent() problem android
when i run the code below everything works fine,it's a simple app with three balls that you can move around...
public class dragndrop extends Activity {
/** Called when the activity is first created. */
private ColorBall[] colorballs = new ColorBall[3]; // array that holds the balls
private static final String TAG="MyTAG";
DrawView myView;
private int balID = 0; // variable to know what ball is being dragged
int X;
int Y;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Point point1 = new Point();
point1.x = 50;
point1.y = 20;
Point point2 = new Point();
point2.x = 100;
point2.y = 20;
Point point3 = new Point();
point3.x = 150;
point3.y = 20;
// declare each ball with the ColorBall class
colorballs[0] = new ColorBall(this,R.drawable.bol_groen, point1);
colorballs[1] = new ColorBall(this,R.drawable.bol_rood, point2);
colorballs[2] = new ColorBall(this,R.drawable.bol_blauw, point3);
myView = new DrawView(this);
setContentView(myView);
}
public class DrawView extends View {
public DrawView(Context context) {
super(context);
setFocusable(true); //necessary for getting the touch events
// setting the start point for the balls
}
// the method that draws the balls
@Override protected void onDraw(Canvas canvas) {
//draw the balls on the canvas
for (ColorBall ball : colorballs) {
canvas.drawBitmap(ball.getBitmap(), ball.getX(), ball.getY(), null);
}
}
// events when touching the screen
public boolean onTouchEvent(MotionEvent event) {
int eventaction = event.getAction();
X = (int)event.getX();
Y = (int)event.getY();
switch (eventaction ) {
case MotionEvent.ACTION_DOWN: // touch down so check if the finger is on a ball
balID = 0;
for (ColorBall ball : colorballs) {
Log.d(TAG,"inside action down inside for coords:"+X+" coords: "+Y);
Log.d(TAG,"ball coords:"+ball.getX()+" coords: "+ball.getY());
int x =X;
int y =Y;
Log.d(TAG,"lalalalalala"+x+" coords: "+y);
if (x > ball.getX() && x < ball.getX()+50 && y > ball.getY() && y < ball.getY()+50){//if (X > ball.getX() && X < ball.getX()+50 && Y > ball.getY() && Y < ball.getY()+50){
Log.d(TAG,"inside ball coords!!!!!!!!!!!!!!!!!!!!!!!!:"+ball.getX()+" coords: "+ball.getY());
balID = ball.getID();
break;
}
}
break;
case MotionEvent.ACTION_MOVE: // touch drag with the ball
// move the balls the same as the finger
if (balID > 0) {
colorballs[balID-1].setX(X-25);
colorballs[balID-1].setY(Y-25);
}
break;
case MotionEvent.ACTION_UP:
// touch drop - just do things here after dropping
break;
}
// redraw the canvas
myView.invalidate();
return true;
}
}
}
But when i try to handle the onTouchevent from the main activity doesn't work and the strange is that it can't read a simple variable(x,y)!!! i can't understand why this happened,it seems it can red them only if it's in a View!!!
public class dragndrop extends Activity {
/** Called when the activity is first created. */
private ColorBall[] colorballs = new ColorBall[3]; // array that holds the balls
private static final String TAG="MyTAG";
DrawView myView;
private int balID = 0; // variable to know what ball is being dragged
int X;
int Y;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Point point1 = new Point();
point1.x = 50;
point1.y = 20;
Point point2 = new Point();
point2.x = 100;
point2.y = 20;
Point point3 = new Point();
point3.x = 150;
point3.y = 20;
// declare each ball with the ColorBall class
colorballs[0] = new ColorBall(this,R.drawable.bol_groen, point1);
colorballs[1] = new ColorBall(this,R.drawable.bol_rood, point2);
colorballs[2] = new ColorBall(this,R.drawable.bol_blauw, point3);
myView = new DrawView(this);
setContentView(myView);
}
// events when touching the screen
public boolean onTouchEvent(MotionEvent event) {
int eventaction = event.getAction();
X = (int)event.getX();
Y = (int)event.getY();
switch (eventaction ) {
case MotionEvent.ACTION_DOWN: // touch down so check if the finger is on a ball
balID = 0;
for (ColorBall ball : colorballs) {
Log.d(TAG,"inside action down inside for coords:"+X+" coords: "+Y);
Log.d(TAG,"ball coords:"+ball.getX()+" coords: "+ball.getY());
int x =X;
int y =Y;
Log.d(TAG,"lalalalalala"+x+" coords: "+y);
if (x > ball.getX() && x < ball.getX()+50 && y > ball.getY() && y < ball.getY()+50){//if (X > ball.getX() && X < ball.getX()+50 && Y > ball.getY() && Y < ball.getY()+50){
Log.d(TAG,"inside ball coords!!:"+ball.getX()+" coords: "+ball.getY());
balID = ball.getID();
break;
}
}
break;
case MotionEvent.ACTION_MOVE: // touch drag with the ball
// move the balls the same as the finger
if (balID > 0) {
colorballs[balID-1].setX(X-25);
colorballs[balID-1].setY(Y-25);
}
break;
case MotionEvent.ACTION_UP:
// touch drop - just do things here after dropping
break;
}
// redraw the canvas
myView.invalidate();
return true;
}
开发者_StackOverflow
public class DrawView extends View {
public DrawView(Context context) {
super(context);
setFocusable(true); //necessary for getting the touch events
// setting the start point for the balls
}
// the method that draws the balls
@Override protected void onDraw(Canvas canvas) {
//canvas.drawColor(0xFFCCCCCC); //if you want another background color
//draw the balls on the canvas
for (ColorBall ball : colorballs) {
canvas.drawBitmap(ball.getBitmap(), ball.getX(), ball.getY(), null);
}
}
}
}
Anyone who knows why?
Yes @bigstones the onTouchevent is working,it captures all the actions,the problem is that if i have the ontouchevent code inside the activity the variables X,Y seems not to work althought that they have a value and i can print it(or log)what i am saying is tested,i've tried and change all the values from the if() statement(getX,getY)to integers and it didn't work only for X,Y.....check the code again please! thanks!
Found it!
I found that the problem is that it was the layout that should be registering some sort of listner so I did this:
I added this code to my Main clas:
private OnClickListener previewListener = new OnClickListener() {
@Override
public void onClick(View v) {
System.err.println("I've been clicked");
}
};
And the this line to the onCreate method:
previewLayout.setOnClickListener(previewListener);
And it worked!
Seemed you moved the onTouch
outside of the DrawView
. Since you're trying to handle touch events, you need to set up a onTouchListener
but not the onClickListener
.
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