Custom Rotating of an image view - android

imageView.SetRotation(theta) centerize the view around the pivot point and rotates the image around this pivot by theta degrees, thats nice, but how can i rotate an image view without first centerizing it around this pivot?
to clearify my question, imagine a board and an image on it, what setRotation does is sticking a pin in the middle of this image and rotate it then, what i want is to pick a pivot - say image's bottom left stick a pin there and then rotate it.
hopefully my question is clear, and solveable!
thanks!

You can set a new pivot point using:
setPivotY(float pivotY);
setPivotX(float pivotX);
After that, the rotation will be made using the new pivot point set by the above methods.
--EDITED--
I used this method to add a ImageView to my layout.
private ImageView addImageView(RelativeLayout mainLayout, int x, int y, int width, int height, OnClickListener onClickListener){
ImageView imageView = new ImageView(this);
imageView.setAdjustViewBounds(false);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.height = height;
params.width = width;
imageView.setLayoutParams(params);
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
imageView.setImageDrawable(getResources().getDrawable(R.drawable.marker_red));
params.leftMargin = x - width/2;
params.topMargin = y - height/2;
imageView.setOnClickListener(onClickListener);
mainLayout.addView(imageView);
return imageView;
}
I called the method with this parameters:
ImageView imageView;
imageView = addImageView(mainLayout, 200, 300, 200, 200, new OnClickListener() {
#Override
public void onClick(View v) {
imageView.setPivotX(200);
imageView.setPivotY(200);
imageView.setRotation(45);
}
});
Finally, you just click on the image, and the image rotates 45 degrees.
regards

Related

RelativeLayout align parent bottom does not align at bottom

I have a custom circular layout using a relative layout:
public class CircularLayout extends RelativeLayout implements OnDragListener {
private DropCallback onDrop = null;
private ImageButton imageButton = null;
private ImageView imageViewBackgroundWave = null;
private int radius = -1;
private double step = -1;
private double angle = -1;
private static final int CENTER_ID = 111;
public CircularLayout(Context context, DropCallback onDrop, int radius, List<View> views) {
super(context);
this.onDrop = onDrop;
this.radius = radius;
this.step = (2 * Math.PI) / views.size();
this.initView(context, views);
}
private void initView(Context context, List<View> views) {
RelativeLayout.LayoutParams layoutParamsView = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
this.setLayoutParams(layoutParamsView);
RelativeLayout.LayoutParams layoutParamsImageview = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
layoutParamsImageview.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
layoutParamsImageview.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
this.imageViewBackgroundWave = new ImageView(this.getContext());
this.imageViewBackgroundWave.setLayoutParams(layoutParamsImageview);
this.imageViewBackgroundWave.setImageDrawable(this.getResources().getDrawable(R.drawable.background_wave));
this.addView(this.imageViewBackgroundWave);
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
layoutParams.addRule(RelativeLayout.CENTER_HORIZONTAL);
layoutParams.addRule(RelativeLayout.CENTER_VERTICAL);
this.imageButton = new ImageButton(context);
this.imageButton.setId(CENTER_ID);
this.imageButton.setLayoutParams(layoutParams);
this.imageButton.setImageResource(R.drawable.ic_power_on);
this.imageButton.getBackground().setAlpha(0);
this.imageButton.setOnDragListener(this);
this.addView(this.imageButton);
for(View view : views) {
this.addView(this.placeView(view));
}
}
private View placeView(View view) {
view.measure(0, 0);
this.imageButton.measure(0, 0);
int x = (int)((view.getMeasuredWidth() / 2) + this.radius * Math.cos(this.angle));
int y = (int)((view.getMeasuredHeight() / 2) + this.radius * Math.sin(this.angle));
this.angle += this.step;
int deltaX = view.getMeasuredWidth();
int deltaY = view.getMeasuredHeight();
int deltaImageX = this.imageButton.getMeasuredWidth() / 2;
int deltaImageY = this.imageButton.getMeasuredHeight() / 2;
int xToDraw = ((x - deltaX) - deltaImageX);
int yToDraw = ((y - deltaY) - deltaImageY);
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
layoutParams.addRule(RelativeLayout.ABOVE, CENTER_ID);
layoutParams.addRule(RelativeLayout.RIGHT_OF, CENTER_ID);
layoutParams.setMargins(xToDraw, 0, 0, yToDraw);
view.setLayoutParams(layoutParams);
return view;
}
#Override
public boolean onDrag(View view, DragEvent event) {
return this.onDrop.onDrop(view, event);
}
}
Unfortunately the imageview (imageViewBackgroundWave) is not aligning at the bottom. It aligns a little bit higher:
So the question is: how can I align my imageview to the bottom of the screen?
The image is exactly as high and as wide as the blue stripe. there is no
padding or white color in it. Its just the blue stripe shown in the picture above.
EDIT:
The background_wave.png:
I use this custom layout in my MenuFragment and call it with the following code:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// ... init the imagebuttons in the list of views
this.circleView = new CircularLayout(this.getActivity(), this, 250, views);
this.circleView.setOnDragListener(this);
this.circleView.setBackground(this.getResources().getDrawable(R.drawable.background));
return this.circleView;
}
You can get the ImageView to stick to the bottom by adding this line of code:
imageView.setScaleType(ScaleType.FIT_END);
The reason for the weirdness is that the ImageView bounds are calculated by the layout engine first, then the image inside the ImageView is scaled to fit the allocated area according to the scale type.
Using WRAP_CONTENT for the ImageView allocates an area based on the size of the unscaled image bitmap - even if it is larger than the screen. Your background_wave.png file is wider than the screen, so a larger area than is needed is allocated. Then afterwards when the image gets fitted inside the layout area using FIT_CENTER it gets shrunk down and centered, so you end up up with white space above and below it.
You can verify this by resizing your background_wave.png to be 1/4 the size: it should align the bottom even without the above code change.
You are setting width and height twice with RelativeLayout.LayoutParams.WRAP_CONTENT and RelativeLayout.ALIGN_PARENT_BOTTOM
Try this:
private void initView(Context context) {
RelativeLayout.LayoutParams layoutParamsView = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
this.setLayoutParams(layoutParamsView);
RelativeLayout.LayoutParams layoutParamsImageview = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
this.imageView = new ImageView(this.getContext());
this.imageView.setLayoutParams(layoutParamsImageview);
this.imageView.setImageDrawable(this.getResources().getDrawable(R.drawable.background_wave));
this.addView(this.imageView);
}
I also recommend you to use visual designer with XML to test layout's rules and parameters, then, if you need it, you can set that rules in code to get the same result.

Android negative margin does not work

I have encountered a problem when i try to give a negative left margin to a LinearLayout.
The negative margin does not appear.
Here is my code
HorizontalScrollView hview = new HorizontalScrollView(context); // HorizontalScrollView is the outer view
RelativeLayout.LayoutParams hs_lot_params = new RelativeLayout.LayoutParams(164, 164);
hs_lot_params.setMargins(100, 100, 0, 0); // set the positions
ImageView image = new ImageView(context);
image.setBackgroundResource(R.drawable.leder);
LinearLayout.LayoutParams img_lot_params = new LinearLayout.LayoutParams(164, 164);
img_lot_params.setMargins(0, 0, 0, 0);
LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.VERTICAL);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(164, 164);
layoutParams.setMargins(-132, 0, 0, 0);
ll.addView(image, img_lot_params);
hview.addView(ll, layoutParams);
Note: my plan is to scroll the image from left to right.
First, the left part of the image is hidden and can scroll to right to see the full image
ViewGroup.MarginLayoutParams params =
(ViewGroup.MarginLayoutParams)view.getLayoutParams(); params.topMargin = -100;
Negative margins should work in LinearLayout and RelativeLayout. What you probably need, is to scroll the HorizontalScrollView with scrollBy(int x, int y) or scrollTo(int x, int y) to achieve the "peek and scroll" effect you described.
Also keep in mind that using raw pixel units is generally a bad idea as the actual size will depend on the pixel density of the screen. Prefer dp measurements instead.

Moving Android View click boundaries after animation

I have two views in a RelativeLayout, both of which fill the screen, so view B is on top of view A. I also have an animation defined which can move view B partially offscreen to show view A underneath. The animation works fine, but I'm having the classic issue of the view bounds not moving with the view, so the button that I use to trigger the animation (which is located on view B) is only clickable from its original position, no matter where view B is located. The issue that I'm having is that after the animation ends, when I set the layout params it's causing view B to be redrawn again, translated from the location of the end of the animation.
As a concrete example, the left edge of view B is initially at x = 0, with a button at x = 450. When the button is pressed, an animation moves the view to x = -400. This works properly - the view is partially off the left hand side of the screen, and the button is now at x = 50, so it is still on screen. The click area for the button though is still at x = 450. So now I set the layout params on view B:
RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) viewB.getLayoutParams();
lp.rightMargin = 400;
viewB.setLayoutParams(lp);
Once the new params are set, the view gets 400px of padding on the right, moving the entire view to x = -800. The clickable area for the button is now properly at x = 50 though, so it seems like I can have it look right or act right. Any idea what I'm doing wrong? Here's how the animation is set up.
Animation anim = null;
anim = new TranslateAnimation(0, -400, 0, 0);
anim.setAnimationListener(this);
anim.setDuration(duration);
viewB.startAnimation(anim);
I was able to get things working by changing the layout params before or after the animation, as appropriate:
private int marginOffsets;
public void triggerAnimation(boolean show, offset)
{
int curX = 0;
int newX = 0;
Animation anim = null;
this.showingPanel = show;
if(show)
{
curX = 0 - offset;
android.widget.RelativeLayout.LayoutParams lp = new android.widget.RelativeLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT);
lp.rightMargin = 0;
rootPanel.setLayoutParams(lp);
}
else
{
newX = 0 - offset;
}
marginOffsets = newX < 0 ? 0 - offset : offset;
anim = new TranslateAnimation(curX, newX, 0, 0);
anim.setAnimationListener(this);
anim.setDuration(duration);
startAnimation(anim);
}
public void onAnimationEnd(Animation anim)
{
//This prevents flicker when the view is moving onscreen.
clearAnimation();
if(!showingPanel)
{
//Move the margin to move the actual bounds so click events still work.
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT);
lp.rightMargin = 0 - marginOffsets;
rootPanel.setLayoutParams(lp);
}
}

Design dynamic hotspot on Image in Android

I have to develop a UI like below:
I want to show this type of image and show hotspot on that image. The position of hotspot will be dynamic, as per x,y and radius provided the circle will be drawn on the original picture. The user can click on the hotspots and onclick action will be defined on the specific hotspot on which the user will click.
What is best process to develop this type of UI?
Make your main layout a RelativeLayout and then you can add programmatically a ImageView with an onClickListener to your layout with the following code:
private void addImageView(RelativeLayout mainLayout, int x, int y, int width, int height, OnClickListener onClickListener){
ImageView imageView = new ImageView(this);
imageView.setAdjustViewBounds(false);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.height = height;
params.width = width;
imageView.setLayoutParams(params);
imageView.setScaleType(ImageView.ScaleType.FIT_XY); //remove this if you want to keep aspect ratio
imageView.setImageDrawable(getResources().getDrawable(R.drawable.ic_launcher)); //here goes your drawable
params.leftMargin = x - width/2;
params.topMargin = y - height/2;
imageView.setOnClickListener(onClickListener);
mainLayout.addView(imageView);
}
to use it you call:
RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.relativeLayout); //this is your main layout
addImageButton(mainLayout, 200, 300, 200, 200, new OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(MainActivity.this, "clicked", Toast.LENGTH_SHORT).show();
}
});
You can also use a ImageButton to achive the same porpose, although the image size will be affected by button border:
private void addImageButton(RelativeLayout mainLayout, int x, int y, int width, int height, OnClickListener onClickListener){
ImageButton imageButton = new ImageButton(this);
imageButton.setAdjustViewBounds(true);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.height = height;
params.width = width;
imageButton.setLayoutParams(params);
imageButton.setScaleType(ImageView.ScaleType.FIT_XY);
imageButton.setImageDrawable(getResources().getDrawable(R.drawable.ic_launcher));
params.leftMargin = x - width/2;
params.topMargin = y - height/2;
imageButton.setOnClickListener(onClickListener);
mainLayout.addView(imageButton);
}
Try it.

How to place ImageButton at x, y location?

I want to place ImageButton at x, y location of my view.
The problem is that Android adds padding around image.
Because I don't know exact size of padding, I cannot place image button at exact location.
So, I want to remove padding.
How can I remove padding around image programmatically?
button.setPadding(0, 0, 0, 0) makes button width shorter and height longer than bitmap.
button.getLayoutParams().width gives minus value.
What I tried so far is like this.
protected class MyLayout extends RelativeLayout {
Bitmap img;
ImageButton button;
public MyLayout(Context context) {
button = new ImageButton(context);
img = BitmapFactory.decodeResource(getResources(), R.drawable.img);
button.setImageBitmap(img);
params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
button.setLayoutParams(params);
params.setMargins(x, y, 0, 0);
button.setBackgroundDrawable(null);
addView(button, params);
}
}
EDIT
Use this...
MarginLayoutParams marginParams = new MarginLayoutParams(image.getLayoutParams());
int left = someValue;
int top = someValue;
marginParams.setMargins(left, top, 0, 0);
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(marginParams);
image.setLayoutParams(layoutParams);

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