Develop Reference

Android - Wrap buttons within view

I am trying to make buttons wrap in a LinearLayout in Android, but they are just continuing off to the right of the view (the word shown in the screenshot should be "HELLO", so I want the "O" to drop down to the next line).
I am adding the buttons programmatically, but even if I code them into the XML layout file, they still don't wrap. Here is the layout file with the LinearLayout container into which I am dynamically adding the buttons:
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constrainedWidth="true"
tools:context=".LetterTileView">
<LinearLayout
android:id="#+id/TilesContainer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constrainedWidth="true"
android:orientation="horizontal">
</LinearLayout>
And here is the code I am using to create and add the tile buttons:
Context context = this;
LinearLayout layout = (LinearLayout) findViewById(R.id.TilesContainer);
LayoutParams params = new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT );
params.setMargins(50, 50, 0, 0);
for (int i=0;i<wordLength;i++) {
Button tileButton = new Button(this);
tileButton.setLayoutParams(params);
tileButton.setText(wordStringtoLetters[i]);
tileButton.setId(i);
tileButton.setBackgroundResource(R.drawable.tile_button);
tileButton.setTextSize(TypedValue.COMPLEX_UNIT_SP, 36);
layout.addView(tileButton);
}
Any advice would be appreciated. Thanks!

I ended up using FlexboxLayout, which works great for this. Thanks to those who offered suggestions!

First of all, there is no need to use a ConstraintLayout you can use your LinearLayout as the parent layout.
Then for the purpose of displaying all buttons in one line, you have to set weight for the LinearLayout in XML and set weight for the views you add to it.
The xml file should look like:
<LinearLayout
android:id="#+id/TilesContainer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:weightSum="5"
app:layout_constrainedWidth="true"
android:orientation="horizontal">
</LinearLayout>
And in code you should set weight for each view you by adding ,1.0f to LayoutParam :
Context context = this;
LinearLayout layout = (LinearLayout) findViewById(R.id.TilesContainer);
LayoutParams params = new LayoutParams( LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT,1.0f );
params.setMargins(50, 50, 0, 0);
for (int i=0;i<wordLength;i++) {
Button tileButton = new Button(this);
tileButton.setLayoutParams(params);
tileButton.setText(wordStringtoLetters[i]);
tileButton.setId(i);
tileButton.setBackgroundResource(R.drawable.tile_button);
tileButton.setTextSize(TypedValue.COMPLEX_UNIT_SP, 36);
layout.addView(tileButton);
}

How to align CenterVertical in Relative layout programmatically

I have a linear layout like this:
<LinearLayout
android:id="#+id/linearLayoutImages"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="horizontal"
android:weightSum="1">
</LinearLayout>
The following function gets a bitmap, sets it to an image view that has been created programmatically, then creates a trash can icon and puts the whole things into a relative layout and finally puts it into the linear layout. But there is a problem, I want the result to be like this:
but the result becomes like this:
Code:
fun setImage(bitmap: Bitmap){
try {
val params = RelativeLayout.LayoutParams(375, 375)
params.addRule(RelativeLayout.ALIGN_PARENT_TOP)
params.setMargins(9,0,9,0)
val imageViewShowPic = ImageView(this)
imageViewShowPic.setLayoutParams(params)
imageViewShowPic.id = View.generateViewId()
imageViewShowPic.requestLayout()
val params2 = RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT)
val relativeLayout = RelativeLayout(this)
relativeLayout.setLayoutParams(params2)
relativeLayout.requestLayout()
val params3 = RelativeLayout.LayoutParams(75,75)
params3.addRule(RelativeLayout.BELOW,imageViewShowPic.id)
params3.addRule(RelativeLayout.CENTER_VERTICAL)
val imageButtonDelete = ImageButton(this)
imageButtonDelete.setLayoutParams(params3)
imageButtonDelete.requestLayout()
relativeLayout.addView(imageViewShowPic)
relativeLayout.addView(imageButtonDelete)
linearLayoutImages.addView(relativeLayout)
imageViewShowPic.setImageBitmap(bitmap)
imageButtonDelete.setImageResource(R.drawable.ic_delete)
imageButtonDelete.setOnClickListener {
linearLayoutImages.removeView(relativeLayout)
}
}
catch (ex:Exception)
{
Toast.makeText(this,ex.message,Toast.LENGTH_SHORT).show()
}
}
Update
The linear layout itself is in a horizontal scroll view, if it makes any difference.
<HorizontalScrollView
android:id="#+id/horizontalScrollViewImages"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:padding="10dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/buttonAddPic">
<LinearLayout
android:id="#+id/linearLayoutImages"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:weightSum="1"></LinearLayout>
</HorizontalScrollView>

(Posted solution on behalf of the question author).
I finally found the solution myself! I changed the relative layout to a vertical linear layout (I don't know if it matters or not):
val params2 = LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT)
val linearLayout = LinearLayout(this)
linearLayout.setLayoutParams(params2)
linearLayout.orientation = LinearLayout.VERTICAL
linearLayout.requestLayout()
and then set the width of imageButtonDelete to match parent.
val params3 = LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT)
val imageButtonDelete = ImageButton(this)
imageButtonDelete.setLayoutParams(params3)
imageButtonDelete.requestLayout()
imageButtonDelete.setBackgroundColor(Color.TRANSPARENT)

Set (RelativeLayout.CENTER_VERTICAL) to (RelativeLayout.CENTER)
val params3 = RelativeLayout.LayoutParams(75,75)
params3.addRule(RelativeLayout.BELOW,imageViewShowPic.id)
params3.addRule(RelativeLayout.CENTER)
and
android:layout_width="wrap_content" to android:layout_width="match_parent"
<LinearLayout
android:id="#+id/linearLayoutImages"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:weightSum="1"></LinearLayout>

With the below code you can achieve the desired output.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/linearLayoutImages"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal"
android:orientation="horizontal"
android:weightSum="1"></LinearLayout>
In Your activity.
try {
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(375, 375);
params.addRule(RelativeLayout.ALIGN_PARENT_TOP);
params.setMargins(9, 0, 9, 0);
ImageView imageViewShowPic = new ImageView(this);
imageViewShowPic.setLayoutParams(params);
imageViewShowPic.setId(View.generateViewId());
imageViewShowPic.requestLayout();
RelativeLayout.LayoutParams params2 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
RelativeLayout relativeLayout = new RelativeLayout(this);
relativeLayout.setLayoutParams(params2);
relativeLayout.requestLayout();
RelativeLayout.LayoutParams params3 = new RelativeLayout.LayoutParams(75, 75);
params3.addRule(RelativeLayout.BELOW, imageViewShowPic.getId());
params3.topMargin = 30;
params3.addRule(RelativeLayout.CENTER_HORIZONTAL);
ImageButton imageButtonDelete = new ImageButton(this);
imageButtonDelete.setLayoutParams(params3);
imageButtonDelete.requestLayout();
relativeLayout.addView(imageViewShowPic);
relativeLayout.addView(imageButtonDelete);
linearLayoutImages.addView(relativeLayout);
imageViewShowPic.setImageResource(R.drawable.ic_launcher_background);
imageButtonDelete.setImageResource(R.drawable.ic_launcher_background);
} catch (Exception ex) {
Toast.makeText(this, ex.getMessage(), Toast.LENGTH_SHORT).show();
}
OUTPUT

setLayoutParams() returning null ptr

I have an xml layout structure something like this:
<?xml version="1.0" encoding="utf-8">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:id="#+id/ll"
android:layout_marginRight="54dp">
<TextView
android:id="+#id/tv"
....
/>
</LinearLayout
I am trying to programatically increase the marginRight of the linear layout. In my Java code i have something like this:
LinearLayout ll = (LinearLayout) findViewById(R.id.ll);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
lp.setMargins(0,0,100,0);
if(something is true){
ll.setLayoutParams(lp);
}
else {
//do nothing
}
I get an null ptr exception on the line ll.setLayoutParams(lp);

"ll" has no parent, so you can't set margin to it, set padding instead, or set margin to the "tv"

Android - positioning views programmatically

I want to figure out how to position views programmatically in android. Lets say for example we have this XML code.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/mainLayout">
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="121dp"
android:layout_marginTop="140dp"
android:text="Results" /></RelativeLayout>
How can I achieve this layout programmatically in android? because I want to have a random position of my textview.

use the RelativeLayout.LayoutParams with the setLayoutParams Method of the TextBox
RelativeLayout.LayoutParams p = (RelativeLayout.LayoutParams)textView1.getLayoutParams();
p.leftMargin = xxx; // in PX
p.topMargin = xxx; // in PX
textView1.setLayoutParams(p)
look up dp to px conversion if u want to use dp values

check this..
RelativeLayout main = new RelativeLayout(this);
main.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT));
TextView textV = new TextView(this);
textV.setGravity(Gravity.LEFT);
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(121, 140, 0, 0);
textV.setLayoutParams(layoutParams);
text.setText("Result ");
main .addView(text);

How to implement horizontal scroll for toolbar in android?

LinearLayout standardtoolbar = new LinearLayout(context);
standardtoolbar.setMinimumWidth(10);
standardtoolbar.setMinimumHeight(50);
Bitmap toolbarBackgroundImage = SkinManager.getInstance().getImageBitmap("BarBackground");
Drawable d = new BitmapDrawable(toolbarBackgroundImage);
standardtoolbar.setBackgroundDrawable(d);
RelativeLayout.LayoutParams lpstandardtool = new RelativeLayout.LayoutParams(5, LayoutParams.WRAP_CONTENT);
lpstandardtool.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
toolbarLayout.addView(standardtoolbar, 0);
/*toolbarLayout.getScrollX();
toolbarLayout.scrollBy(5, 0);
toolbarLayout.setScrollBarStyle(0);
*/
ScrollView scroll = new ScrollView(AppController.getInstance().getCurrentActivity());
scroll.addView(toolbarLayout);
the scroll view is not working for the given layout. The commented code was written for horizontal scroll view. But its not working.

in your xml file example.xml
<HorizontalScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="wrap_content" android:layout_width="wrap_content>
<LinearLayout android:id="layout" android:layout_height="wrap_content" android:layout_width="wrap_content" android:orientation="horizontal">
</LinearLayout>
</HorizontalScrollView>
in java code
LinearLayout standardtoolbar = (LinearLayout)findViewById(R.id.layout);
.
.
.
layout.addView(standardtoolbar, 0);