Develop Reference

Using setLeft/setRight methods on new textview

I'm working with TextViews progammatically and I need to dynamically add new views and set their left/top position in the RelativeLayout parent.
What I'm doing is something like this:
RelativeLayout global=(RelativeLayout)findViewById(R.id.global);
TextView view=(TextView)findViewById(R.id.root);
RelativeLayout.LayoutParams lp=new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
final TextView childView=new TextView(view.getContext());
lp.addRule(RelativeLayout.ABOVE, view.getId());
childView.setLayoutParams(lp);
childView.setId(childView.getId()+1);
childView.setText("TRY STRING");
childView.setTextSize(view.getTextSize());
childView.setWidth(view.getWidth());
childView.setLeft(view.getLeft()+interval);
global.addView(childView);
Basically, I have a textview in a certain position (which is called view) and I'm trying to create a new textview above the existing one and on the same left position.
Although the getLeft() method correctly returns the left position of view, childView happens to have the left field set to zero, and appears at the left end of the screen when i add it to the RelativeLayout.
It looks like it's completely ignoring the setLeft method!
Can anyone explain why?
Thank you very much in advance!

public final void setLeft (int left)
Added in API level 11
Sets the left position of this view relative to its parent. This method is meant to be called by the layout system and should not generally be called otherwise, because the property may be changed at any time by the layout.
Parameters
left The bottom of this view, in pixels.
most likely the left value is being set by the layout every time it is drawn and overrides the value that you are setting on your view.
android layouts are very XML ish even when doing it programmatically.
try using
lp.setMargins(int left, int top, int right, int bottom);
..or some other method that won't be undone when the layout is drawn

Change the height of a relative layout multiple times

I'm using the following code to change the height of a relative layout that contains a listview. It works fine the first time I call it, but if i call the same code again later to change the height to a different value it does nothing. Why is this and how do I make it work?
LayoutParams params = myrelativelayout.getLayoutParams();
params.height = newHeight;

Try to add myrelativelayout.setLayoutParams(params); every time you change it. This will make sure the view is invalidated each time and that you update the Actual params object for the view.

RelativeLayout add rule "RelativeLayout.LEFT_OF" not working

I have a relativeLayout like below:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:id="#+id/parent" >
<ListView
android:layout_width="360dp"
android:layout_height="600dp"
android:id="#+id/list"
android:inputType="text"
android:maxLines="1"
android:layout_margin="50dp"
android:layout_alignParentRight="true"
/>
</RelativeLayout>
In the java code, I want to add a view to the left of the listview, but it didn't worked:
m_relativeLayout = (RelativeLayout)findViewById(R.id.parent);
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
layoutParams.addRule(RelativeLayout.LEFT_OF, m_listView.getId());
Button button2 = new Button(this);
button2.setText("I am button 2");
m_relativeLayout.addView(button2, layoutParams);
only if I set the listview to alignParentRight, it will work. Is this an android bug or I'm missing something?
I always try addView(View child, int index, LayoutParams params), but it might only work in the linearlayout. So is there an normal solution to make the RelativeLayout.LEFT_OF work?
EDIT
I have tried RelativeLayout.BELOW and RelativeLayout.RIGHT_OF, and they worked perfectly, so it means I don't have enough place to get the button? I tried to give more space, but it still not work.
I use Toshiba AT100 (1280*800) and landscape, so the space is enough. Test below and right just same as the left. I think If i put an control A in the relativelayout, then I add control B and decalare it's on the left of the control A, the result should be the control B will push the control A to its right, right?

I think If i put an control A in the relativelayout, then i add control B and declare it's on the left of the control A, the result should be the control B will push the control A to its right, right?
Your assumption is incorrect, the control A will not be pushed to the right unless you specified this with a RelativeLayout.LayoutParams rule. RelativeLayout places its children one one top of each other starting at the top-left corner of the screen if you don't specify placement rules for them. When you add the View A to the RelativeLayout without any rules(like layout_alignParentRight) it will be placed starting from the top-left corner of the screen. Then, when you add the View B, the rule to_leftOf will apply to this View position but this rule doesn't mean anything for the View A who will maintain its position on the screen. This will make View B to be place to the left of View A but outside of the screen as View A bounds start from the left border of the screen.
The Button will be placed to the left of the ListView when you use layout_alignParentRight="true" because there is now space to actually see the Button(it's not outside anymore). addView(View child, int index, LayoutParams params) works in a LinearLayout because the LinearLayout arranges its children in a row or column(depending on orientation) so when you add a View at a specific position, it will push the other Views after it to the right or below(depending on orientation)(there is no relative positioning of the views in a LinearLayout, the only rule is that the children come one after the other).
Starting with the ListView without any rules set on it, here is an example on how to make the Button to appear on the left of the ListView:
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
Button button2 = new Button(this);
button2.setText("I am button 2");
button2.setId(1000);
m_relativeLayout.addView(button2, layoutParams);
RelativeLayout.LayoutParams rlp = (RelativeLayout.LayoutParams) m_listView
.getLayoutParams();
rlp.addRule(RelativeLayout.RIGHT_OF, button2.getId());
The Button will be added as normal to the screen and it will appear starting from the top-left corner of the screen. Without the two lines from the code above the Button and ListView will overlap as this is the normal behavior of RelativeLayout for children without any rules on them. We then explicitly modify the position of the ListView to move it to the right(with the last two line from the code above).

If your variable names are indicative, it's because you are adding the widget to a LinearLayout, so tags for a RelativeLayout get ignored.
This line is the one I'm talking about:
m_linearLayout.addView(button2, layoutParams);
EDIT
You say alignParentRight works... the only difference there is that ot doesn't take an anchor parameter. Perhaps m_listView.getId() isn't returning the proper id. You could step through with the debugger and see if it's returning a proper value.
Maybe you could try calling the id specifically...
layoutParams.addRule(RelativeLayout.LEFT_OF, R.id.list);

To perform it, use predefined view ID or declare one. In values folder create ids.xml then add a Item like this:
<item name="imageViewID" type="id"/>
use this id in your code where you are creating new Instance of view like this:
RelativeLayout layout=new RelativeLayout(context);
ImageView imageView = new ImageView(context);
imageView.setId(R.id.imageViewID);
RelativeLayout.LayoutParams layoutParams = new LayoutParams(50, 50);
layoutParams.addRule(RelativeLayout.CENTER_HORIZONTAL);
layout.addView(imageView, layoutParams);
TextView textView = new TextView(context);
RelativeLayout.LayoutParams textViewParams= new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
textViewParams.addRule(RelativeLayout.CENTER_HORIZONTAL);
textViewParams.addRule(RelativeLayout.BELOW, imageView.getId());
layout.addView(nameView, nameLayoutParams);
or we can directly use this function View.generateViewId() to perform the same. Like this:
imageView.setId(View.generateViewId());

I think you might have forgotten to add m_listView to the RelativeLayout or m_listView's visibility would be GONE.
Can you please check for that?

setId before align is called, especially for the new object view.

If you are using a custom id and not a regular generated Android id (eg. R.id.my_id), make sure that the id is not equal to 0 (or negative), otherwise the rule will be ignored.

How to bring Animation to front: bringToFront and zAdjustment/Z-ordering

I have a LinearLayout with two views in it, next to each other. When a view is tapped upon, it animates to full screen. This goes fine for the view on the right, but it fails for the left view:
I am unable to animate the left view on top of the right view
Without corrupting my layout with bringToFront(). Adjusting the Z-order of my animation does not seem to work.
Not a solution: The problem is gone when I use "brintToFront()" on the left view, but this causes my layout to be completely corrupted afterwards, and there is no brintToBack() function or whatsoever. => brintToFront = not a good solution?
Adjusting the Z-order of my animation does not seem to work (does not change anything).
scaleAnimation.setZAdjustment(Animation.ZORDER_TOP);
translateAnimation.setZAdjustment(Animation.ZORDER_TOP);
AnimationSet set = new AnimationSet(true);
set.addAnimation(scaleAnimation);
set.addAnimation(translateAnimation);
set.setZAdjustment(AnimationSet.ZORDER_TOP);
myFrameLayout.startAnimation(set);
Why does Z-ordering not work as expected?

This should be possible if you extend LinearLayout and override the following method:
getChildDrawingOrder (int childCount, int i)
To make sure layout uses your function you need to call setChildrenDrawingOrderEnabled(true)
See ViewGroup javadoc

For your z reordering will apply you gonna need to request a new layout on the view, but try doing it before starting your animation:
AnimationSet set = new AnimationSet(true);
// init animation ...
scaledView.bringToFront();
scaledView.requestLayout();
myFrameLayout.startAnimation(set);

I guess there is no good answer to this.
I am now animating everything else on the screen too, so if view 1 has to grow larger on top of view 2 than I animate view 2 also, in such a way that it looks like view 1 is growing on top of view 2, while actually view 2 is getting smaller while view 1 is getting larger.
Quite a lot of work and a bad solution, but I guess the only solution.

Remove rule from RelativeLayout

I have bookmark ImageButton with ALIGN_WITH_PARENT set to true in XML.
If I programatically do (I want to remove that rule)
RelativeLayout.LayoutParams params = (LayoutParams) bookmark.getLayoutParams();
params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, 0);
bookmark.setLayoutParams(params);
The rule just doesn't apply (in my layout I can see that rule is still active) -> layout isn't good. If I manually do it (some sort of "simulation", set ALIGN WITH PARENT to false) in my Layout Editor, my layout is fine which leads to this code up there. Something is wrong.
What?

(I believe temporary) Solution is to wrap up that ImageButton in one dummy RelativeLayout and then take the params of that dummy layout and add or remove rules. That way it's working just fine.

Insead of calling setLayoutParams(), try to use requestLayout() method:
bookmark.requestLayout();
From API docs:
Call this when something has changed which has invalidated the layout of this view. This will schedule a layout pass of the view tree.

simply call removeRule() function on params.
for example,
params.removeRule(RelativeLayout.CENTER_IN_PARENT);