Develop Reference

android set width and height to 100% of a dynamically created button

that might be a silly question but i didn't find any answer on the internet.
I want to create a button that fills the whole screen (width = 100%, height = 100%) when pressing another button.
Therefore i tried this:
Button button = new Button();
button.setText("fills screen");
button.setWidth(100);
button.setHeight(100);
the problem is that the setWidth and setHeight methods are dealing with px and not with percent.
What do i need to add to use percent values instead of px values?

I'll link here a post that details how to set a width programmatically
programmatically set button width to 50 of parent linearlayout
You can utilize that method (except do not divide by 2 JohnEye demonstrates in his answer)
Or you can utilize the LayoutParams class and create a new instance that will have the parameters set and pass those parameters to your object.
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
button.setLayoutParams(lp); // Assuming you've already initiated it of course as above
MATCH_PARENT will fill up the view. If the root view is the highest view on the hierarchy then this will work, as it will fill up the entire view. If not, the button would need to be moved there. (It may be your linearLayout or some other view)
Hope this helps.

Android: How to dynamically place views with relative spacing

I am dynamically placing views into a RelativeLayout. Currently, I am doing:
layoutParams = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(0, position, 0, 0);
relativeLayout.addView(textViewInstance, layoutParams);
where position is incremented by a fixed amount after each TextView object is added to the layout. The problem is that some of the TextViews contain long strings, which makes for awkward formatting on devices with smaller screen sizes because the string will spill into multiple lines and bleed into the whitespace.
Is there any way I can add these TextViews with spacing relative to the TextView right above it? I want to achieve something to the effect of:
layoutParams = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(0, previousTextViewInstance.bottomPixel + 50, 0, 0);
relativeLayout.addView(textViewInstance, layoutParams);
where previousTextViewInstance will be saved after each new TextView is added.
Is this possible?

Instead of setting margin for each view, you can dynamically add each view below the previous one in relative layout.
For that, first set an id for each of your textView.
firstTextView.setId(textView_id_1);
while adding second textView, set rule for layout params as:
layoutParams.addRule(RelativeLayout.BELOW, textView_id_1);
secondTextView.setLayoutParams(layoutParams);
secondTextView.setId(textView_id_2);

Two ways of specifying the height of an android Layout?

Im having problems specifiying the height of a relative Layout. From what i understand, these two blocks of code should be equivalent (myLayout is a RelativeLayout that i defined in XML, with an initial height of "0dp", and it's parent is also a RelativeLayout):
BLOCK 1:
RelativeLayout.LayoutParams p = (RelativeLayout.LayoutParams)myLayout.getLayoutParams();
p.height = (int)(35*scale);
myLayout.setLayoutParams(p);
myLayout.invalidate();
BLOCK 2:
RelativeLayout.LayoutParams p = (RelativeLayout.LayoutParams)myLayout.getLayoutParams();
RelativeLayout.LayoutParams newP = new RelativeLayout.LayoutParams(p.width, (int)(35*scale));
myLayout.setLayoutParams(newP);
myLayout.invalidate();
Scale, in my case, is 2.
So i expect myLayout to have a height of 70 after the execution of either of these blocks, and i expect it to return that height when i call myLayout.getHeight(). Also, i expect myLayout to occupy a rect with the height of 70 and its former width (happens to be match_parent).
But when i run the code, the first block does not change the height of myLayout on screen, nor does it change the return value of myLayout.getHeight(). It does, however, change myLayout.getLayoutParams().height.
Now the second block does work, although i have to run it twice(!?) for the change to take effect. Im seriously at a loss here and i cant find anything even closely related to this in the docs.
I thought this would be an easy task when i set out yesterday, but by now im questioning my sanity, among other things. Any Ideas?

If size is determined dynamically, you may need to use ViewTreeObserver to get the size seen on the screen.
Set your width and height in defining your params. If you want the width to be match_parent, change your code like below and it is going to work (if you don't want match_parent, just set the width that you desire in the code below):
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
LayoutParams.MATCH_PARENT, (int)(35*scale));
myLayout.setLayoutParams(params);

Center view in android after changing its width properties

I'm changing the width of a grid view based on its column width and number of columns (which works):
gridView.setLayoutParams(new LinearLayout.LayoutParams(gridManipulation.getColumnWidth() * (int)Math.sqrt(str.length) + 10, LayoutParams.FILL_PARENT));
gridView.setGravity(Gravity.CENTER);
I've tried re-centering it in the parent view but its not working, does anyone know why, its still centred as if it still has the width parameters before my dynamic change.

Set the Gravity as LayoutParams property then set that LayoutParams to your GridView as follows...
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(gridManipulation.getColumnWidth() * (int)Math.sqrt(str.length) + 10, LayoutParams.FILL_PARENT);
params.gravity = Gravity.CENTER;
gridView.setLayoutParams(params);

you cant center it if its bigger than its parent, which is never bigger than the screen, unless you set it manually, which will cause the system to render data outside the screen and slow you way down.....
is it expanding verticaly or horizontally or both? my recomendation would be to put it in a scrollview.

Set EditText to percentage of parents's width in LinearLayout

I have a LinearLayout class in which I have:
TexView | ImageView | EditText | ImageView.
I have the last ImageView all the way to the right side of the LinearLayout its wrapped in. The EditText runs very long and in some case pushes the last ImageView out of view (or so it seems to push it out of view).
I want to to have the EditText set to a percentage of the total width. I tried using weight with LinearLayout parameters but it seems to cause the view to get all out of wack. For example here it is for the EditText:
LinearLayout.LayoutParams lpEt = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT,
.50f);
All the other views follow suit but have lesser weights (.2, .2, .1) and they all add up to 1.0. But the LinearLayout row is never spaced correctly.
Should I find out the width of the parent (which is a ListView) and then set the width of the EditText explicitly based on the parent's width or is there a better way?

Im not sure what your linear layout orientation is but im guessing its horizontal. if so try this.
LayoutParams textViewParams = new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
textView.setLayoutParams(textViewParams);
LinearLayout.LayoutParams editTextParams = new LinearLayout.LayoutParams(
0,LayoutParams.WRAP_CONTENT,1f);
editText.setLayoutParams(editTextParams);
LayoutParams imageViewParams = new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
imageView.setLayoutParams(imageViewParams);
This will make the edit text to fill the remaining space between the textview and imageview. If you need something else, just modify the code a bit. When using weights, set the weight or height as 0 for which you are setting weight for.