Java method for android:layout_gravity-ThrowExceptions

Exception or error:

I would like to know if is there a way to call android:layout_gravity property from a Java method. I didn’t found any method in Android documentation to do it. This is the picture of the layout I want to implement:

http://www.anddev.org/resources/image/2234

I know to do it through XML, as following:

<FrameLayout
    xlmns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">

      <Button
         android:layout_gravity="left|center_vertical"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="<" />


      <Button
         android:layout_gravity="right|center_vertical"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text=">" />
</FrameLayout>

But in my situation, I need to do it through Java code, because I’ll implement another layout views dynamically. To avoid merging XML layout with Java code, I would prefer make all layout using Java.

How to solve:

Well as far as I understand you looking for this It is for FrameLayout for other layout see appropriate LayoutParams classes. For setting gravity like in your XML use something like:

FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT,Gravity.LEFT | Gravity.CENTER_VERTICAL)

followed by addView with newly constructed LayoutParams

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Maybe I misunderstand you, but here it is:

http://developer.android.com/reference/android/widget/TextView.html#setGravity(int)

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Watchout! This wouldn’t work with LinearLayout though. Because LinearLayout.LayoutParams(…) constructor is different from FrameLayout.LayoutParams(…) constructor. The third parameter is not gravity but weight.

     LinearLayout.LayoutParams(int width, int height, float weight)

as opposed to

     FrameLayout.LayoutParams(int width, int height, int gravity)

and this call, despite not producing compiler error is actually wrong:

lparams = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, Gravity.LEFT);

###

button.setBackgroundResource(R.drawable.sound_on);
        button.setText("On");
        button.setGravity(Gravity.CENTER_VERTICAL| Gravity.RIGHT);
        button.invalidate();

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To change the layout_gravity attribute for an existing view:

Button button = (Button) findViewById(R.id.some_button);
FrameLayout.LayoutParams params;
params = (LayoutParams) button.getLayoutParams();

params.gravity = Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL;
button.setLayoutParams(params);

The button is contained in a FrameLayout which has a gravity attribute corresponding to the layout_gravity XML attribute. Documentation link.

###

before adding the button, you should change the orientation of your layout

yourbutton.setGravity(Gravity.RIGHT);
LayoutParams layout = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, Gravity.RIGHT);
layout.gravity = Gravity.RIGHT;
yourbutton.setLayoutParams(layout);


yourlayout.setGravity(Gravity.RIGHT);
yourlayout.addView(yourbutton);

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