I have a FrameLayout that contains several ImageView. On the main activity, I record the touch events in order to move my FrameLayout and the images inside with the finger (drag).
For doing so, I am calling canvas.translate(x,y) inside the onDraw of the framelayout which is called by a invalidate() in the activity touch event handler.
Everything works like a charm except that after the translate, I am not able to click on my ImageView. In fact, the click listener of each image is still at the original place before the translate.
I have read that I should manually update the layout of each image after the translate but how to do that ? If I change the margin with the translate value, the images are going two times further ...
I would really appreciate any help on that one.
Cheers.
Here is the frameLayout where I translate the canvas in the onDraw() method (the ImageView are added to that FrameLayout in my main Activity).
public class TopView extends FrameLayout {
public float mPosX = 0;
public float mPosY = 0;
public TopView(Context context)
{
super(context);
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(1920, 3200, Gravity.CENTER);
this.setLayoutParams(lp);
setWillNotDraw(false);
}
#Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.translate(this.mPosX, this.mPosY);
}
}
You can use setPadding(this.mPosX,this.mPosY,0,0) in the the constructor. It should work.
Related
I'm making a custom View thats derived from an ImageViewand I control where the image has to be within this ImageView using padding.
I have set OnClickListener on my custom ImageView that resizes it:
image.setOnClickListener(new ImageView.OnClickListener(){
#Override
public void onClick(View v) {
image.resize_image();
}
});
and this is how this function is looking like
public void resize_image(){
ViewGroup.LayoutParams params = getLayoutParams();
params.height = new_heigth;
params.width = new_width;
setLayoutParams(params);
}
After this resizing is done I don't want my displayed image to change size (only the custom ImageView is changing size so I can draw an extra stuff around this image) within my custom ImageView so inside onDraw(Canvas) member function I set the new padding
class custom_ImageView extends ImageView{
//...
#Override
protected void onDraw(Canvas canvas) {
//...
setPadding(new_left_padding, new_top_padding, new_right_padding, new_bottom_padding);
//...
}
//...
}
Result is that width and heigth are changed like I wanted but my displayed image is neither in the right position or size.
Interesting this is that if I add an extra line of invalidate(); in the end of my resize_image() and I click on my custom_ImageView twice - on the 2nd click image draws itself in right size and position like I wanted.
Can anyone tell me why this is happening?
I kind of worked around this by not using ImageView at all but just drawing image where it needs to be by using Canvas.drawBitmap(Bitmap, RectF, RectF, Paint)
This way I don't have to specify images location using setPadding within onDraw, but I can do it simply by specifying position using RectF.
I have created a custom view class to use in a project I'm working on. To put is simply, I'm displaying an image, then adding images on top of the original image (currently by clicking on the image, but that's not final).
I have these 2 methods in my custom view:
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
for (Drawable d : drawableList)
{
d.draw(canvas);
}
}
public void AddPoint(float x, float y)
{
Drawable tempDrawable = pin;
tempDrawable.setBounds((int)x, (int)y, (int)x + 50, (int)y + 50);
drawableList.add(tempDrawable);
invalidate();
}
The AddPoint() method is called in an OnTouchListener and is passes the coordinates of the touch event.
The way it currently works is it displays the main image, but will only display the most recent images where I clicked, previous ones just disappear.
Does anybody know what I am doing wrong here?
I've figured out what I was doing wrong.
The line of code:
Drawable tempDrawable = pin;
I changed to:
Drawable tempDrawable = mainRes.getDrawable(R.drawable.pin);
I got mainRes from the init(Context context) method I wrote in the custom View class.
I,m taking my first step into movement of bitmaps. From bits on the internet i,ve created this simple code. The bitmap moves across the screen from top left to top right it goes off the screen and back on at 0,0. What i want to do is add a button or method to manually move the image. I,m only using this single class and have noticed it does not use the main_activity xml Or does it?? If someone could show me on this 1 direction i can duplicate for the other directions. If youd like to add code so doesnt go off screen would be a bonus
public class MainActivity extends Activity {
int x=0;
int y=0;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new myView(this)); }
private class myView extends View{
public myView(Context context) {
super(context); }
#Override
protected void onDraw(Canvas canvas) {
Bitmap myBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.richinch);
if (x < canvas.getWidth()){x +=10;}
else {x=0;}
canvas.drawBitmap(myBitmap, x, y, null);
invalidate();
}}}
Ive added this to the code and read a little on OnTouch listener. How would i add that to the region or Rectangle this would be very helpfull so effectively i,m using the Bitmap as a button if was button id know with onclick, Basicall im trying to make 2 Bitmap buttons to move the image Left Right for now.Eventually all directions. Please use names im using unless creating summit eg int etc
Paint green = new Paint();
green.setColor(Color.RED);
green.setStyle(Paint.Style.FILL);
////creating the shape////
Rect rect= new Rect();
rect.set(0, 0,x+50, x+50);
canvas.drawRect(rect,green);
Region region = new Region(0, 950, 100, 1030);
I am not exactly sure what you want to achieve, but if you would like to make an animation, avoid using onDraw() and just let ObjectAnimator do the "moving" for you. Here's a detailed tutorial on it.
The minimum code you need:
ObjectAnimator animation = ObjectAnimator.ofFloat(yourObject, "x", xDest);
animation.setDuration(500); // milliseconds
animation.start();
You are not using any xml
this part here:
setContentView(new myView(this)); is where you would add your xml file setContentView(R.layout.mainxml)
If you want to move around a bitmap with the touch of your finger check out these tutorials. They do exactly this and you will learn to use a SurfaceView
http://www.eis4u.com/2012/02/13/playing-with-graphics-in-android-part-i/
http://www.eis4u.com/2012/02/13/playing-with-graphics-in-android-part-ii/
http://www.eis4u.com/2012/02/13/playing-with-graphics-in-android-part-iii/
I have drawn a bitmap image over a canvas.
Bitmap image = BitmapFactory.decodeResource(getResources(), R.drawable.sq);
canvas.drawColor(color.black);
Rect dstRectForRender = new Rect(0,0,320,450);
canvas.drawBitmap(image, null,dstRectForRender,null);
The image gets displayed based on my screnn on a cnavs.
On my touch input, I need to pass the x and y co-ordinate position of the image and fill that pixel with a color to show that the image is painted on a drag event.
How can I pass the x and y coo-ordinate parameters? Which functions should I use to plot the pixels on the image?
I appreciate your help and sweet time.
I'm not sure if this is the best way to do this, but it would be much easier to do this if you defined your own subclass of ImageView and name it something like DrawableImageView. You'd have to make sure you implement all the basic constructors from ImageView, then override the onTouchEvent method. From that event you can get the touch coordinates and store them in an ArrayList<Point> and use that ArrayList by overriding the onDraw method and "painting" the image.
public class DrawableImageView extends ImageView {
ArrayList<Point> list = new ArrayList<Point>();
//constructors..
#Override
public boolean onTouchEvent (MotionEvent event) {
float x = event.getX();
float y = event.getY();
list.add(new Point(x,y));
invalidate();
}
This is just a very brief overview of how to start your class, and may not be the most accurate way of doing things (depending on your specific code). Now, instead of using <ImageView> tags in your xml (or, loading an ImageView programatically), you refer to your subclass like so:
<your.package.name.DrawableImageView
/>
Edit
In response to your comment, there is no predetermined way to draw over an image. You must implement this yourself, which is why I recommended storing Points in an ArrayList. I'm not really sure what you're trying to achieve here, but to draw (for example) black dots over an image you have to override onDraw:
public void onDraw(Canvas c) {
super.onDraw(c);
for(Point p : list) {
//Draw black point at x and y.. I'm posting from my cell so I can't go into much detail
}
}
Also, to force a View to redraw itself you need to use the invalidate() method in your onTouchEvent() (which I've added above).
I am new for android. I want to add image button in onDraw. I wonder if I can do like this. I don't have compile error. But simulator says, "Unfortunately MyApp has stopped."
My second question is how can I add button at x, y location in screen?
There is no location parameters in addView.
protected class MyLayout extends LinearLayout {
ImageButton button;
public MyLayout(Context context) {
super(context);
setWillNotDraw(false);
button = new ImageButton(context);
button.setImageBitmap(buttonBitmap); // buttonBitmap is loaded in onCreate
}
public void onDraw(Canvas canvas) {
addView(button);
}
}
I would not be adding a button to a custom linearlayout in the onDraw() override function. onDraw is called periodically (for example when the element is resized). So you will be adding the same button EACH time onDraw() is called. And you will get an error if you add the same item more than once.
What exactly are you trying to do? If you want to just add a button to a linear layout, you can do so without extending a layout.