Develop Reference

Android : Unable to change width of dynamic button

I am trying to make dynamic buttons of fixed dimensions. I am able to alter the height but unable to change the width. The width of the button seems to MATCH_PARENT (it takes up whole screen width. If there are two buttons, each button width is half screen width and when there is only one button, button width is screen width).
TableLayout table = (TableLayout)findViewById(r.id.table);
TableRow tableRow = new TableRow(this);
table.addView(tableRow);
Button button = new Button(this);
button.setLayoutParams(new TableRow.LayoutParams(30,30));
tableRow.addView(button);
Could anybody point out where I am going wrong.

Only This You have to do to change Button Dynamically
First I get Button
Button btn = (Button) findViewById(R.id.button1);
Then Button Click event I put This Code Only
TableRow.LayoutParams lp = new TableRow.LayoutParams(70, 70);
btn.setLayoutParams(lp);
And Works Fine. Try It. Will solve your Problem

Instated "button.setLayoutParams(new TableRow.LayoutParams(30,30));" change to following code change the button Height and Width.
LayoutParams lp = new LayoutParams(40, 40);
table.addView(button, lp);

WHEN to programmatically resize a button created programmatically?

I am creating some buttons in a tablelayout. I am creating the buttons programmatically.
For example the following code is in the "onresume" method...
TableLayout.LayoutParams tableParams = new TableLayout.LayoutParams(TableLayout.LayoutParams.WRAP_CONTENT, TableLayout.LayoutParams.WRAP_CONTENT);
TableRow.LayoutParams rowParams = new TableRow.LayoutParams(0,android.widget.TableRow.LayoutParams.MATCH_PARENT,3f);
TableLayout tableLayout = (TableLayout) findViewById(R.id.sometablelayoutivealreadydefinedinxml);
TableRow tableRow = new TableRow(this);
tableRow.setLayoutParams(tableParams);
Button btnOne = new Button(this);
btnOne.setId(100);
btnOne.setLayoutParams(rowParams);
btnTwo.setId(200);
btnTwo.setLayoutParams(rowParams);
tableRow.addView(btnOne);
tableRow.addView(btnTwo);
tableLayout.addView(tableRow);
I want to set the height of the button to be the SAME as the width. The width is determined by the size of the screen. The problem as I understand it,is that until the buttons are actually drawn to the screen they don't exist so any width returned will be zero. So I tried the following code.
Button yourBtn = (Button)findViewById(100);
int btnSize;
btnSize = yourBtn.getWidth();
yourBtn.setLayoutParams(new TableRow.LayoutParams(btnSize, btnSize));
Now the problem is that if I run this code immediately after creating the buttons the width of the button is returned as 0 as the button hasn't been drawn yet. However, if I assign the code to a test button then it resize the button as I want it to. However, I don't want the user to have to press a button after the screen has loaded to resize the buttons properly.
So, the question is when is the appropriate time to call this to resize the buttons properly when the activity is created but after the buttons have been drawn and how do I do this?

Issue with Button in AlertDialog (Floating off screen)

Here's an image of what my issue looks like:
That box at the bottom is the top half of a button. Whenever I've got too many Stock Options in the dialog box, it first forces the button off screen, THEN it scrolls.
I want the button fixed at the bottom of the dialog and then have the scrolling happen.
Here's the code:
public void buyStock(View view){
Context context = getApplicationContext();
//create ScrollView to hold everything
ScrollView scrollView = new ScrollView(context);
//generate content for dialog
LinearLayout dialogContainer = new LinearLayout(context);
dialogContainer.setOrientation(LinearLayout.VERTICAL);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, 400, 1);
dialogContainer.setLayoutParams(params);
dialogContainer.setPadding(15, 15, 0, 15);
dialogContainer.setBackgroundColor(Color.WHITE);
//each hotel stock options
for (int i = 0; i < hotels.size(); i++) {
Hotel testHotel = hotels.get(i);
testHotel.setPrice(200);
View stockPicker = getStockPicker(testHotel);
LinearLayout.LayoutParams pickerParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, 100, 1.0f);
pickerParams.gravity = Gravity.LEFT;
stockPicker.setLayoutParams(pickerParams);
dialogContainer.addView(stockPicker);
stockPicker.setBackgroundColor(0xffffff);
}
scrollView.addView(dialogContainer);
LinearLayout dialogLayout = new LinearLayout(context);
dialogLayout.setOrientation(LinearLayout.VERTICAL);
Button buyButton = new Button(context);
LinearLayout.LayoutParams buttonParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, 100);
buyButton.setLayoutParams(buttonParams);
LinearLayout buttonLayout = new LinearLayout(context);
buttonLayout.addView(buyButton);
dialogLayout.addView(scrollView);
dialogLayout.addView(buttonLayout);
ContextThemeWrapper ctw = new ContextThemeWrapper(this, R.style.AppTheme);
AlertDialog.Builder buyStockDialog = new AlertDialog.Builder(ctw);
buyStockDialog.setTitle("Buy Stock: ");
buyStockDialog.setView(dialogLayout);
buyStockDialog.show();
}

Make dialogLayout a RelativeLayout, and then declare buttonParams as a RelativeLayout.LayoutParams (layout params are declared according the parent viewgroup type, which for buyButton is now a RelativeLayout). Your also going to need to declare a RelativeLayout.LayoutParams for scrollView.
note: This code is in c#/monodroid, not raw java/android, so some quick porting of some of the methods and constants may need to be required, but shouldn't be too time consuming.
If this doesn't work out exactly trying experimenting with other combinations of the RelativeLayout position rules and/or gravity. Let me know if it doesn't work out.
RelativeLayout.LayoutParams scrollParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, some_height);
RelativeLayout.LayoutParams buttonParams = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, 100);
Then, add these statements to control where scrollView and buyButton are positioned
scrollParams.AddRule(LayoutRules.AlignParentLeft);
scrollParams.AddRule(LayoutRules.AlignParentTop);
buttonParams.AddRule(LayoutRules.Below, scrollView.Id);
The for the getting the button on the bottom of the screen, try one of two things
buttonParams.AddRule(LayoutRules.AlignParentBottom);
or
buyButton.Gravity = Gravity.BOTTOM

Try explicitly setting a fixed height to the scrollView
scrollView.LayoutParameters.Height = HEIGHT;
I think it defaults to WRAP_CONTENT if not specified, and is why its scaling.
You may have to set it in a layout file if you cant from code
<ScrollView
android:id="#+id/scroll_view_1
android:layout_width="wrap_content"
android:layout_height="100"/>
and then change
ScrollView scrollView = new ScrollView(context);
to
ScrollView scrollView = findViewById(R.Id.scroll_view_1, this);

Try wrapping the scrollView in another LinearLayout, and set this new layout's height to a fixed width that keeps the button low enough to your liking. You can actually replace the Scrollview with a ListView, but don't do this until after at least trying to get this fix working first. ListViews scroll, but you'd still face this problem without this fix.
To fix the new issue you mentioned below (with some quick and dirty code, you should use trial and error to fix it correctly), try the following
//each hotel stock options
for (int i = 0; i < hotels.size(); i++)
{
// ...
}
if( hotels.size() < numberOfItemsNeededForCorrectView )
{
for( int i=0; i < numberOfItemsNeededForCorrectView - hotels.size(); i++ )
{
View blankView = new View(context);
LinearLayout.LayoutParams viewParams = new LinearLayout.LayoutParams(1, 100);
blankView.setLayoutParams(viewParams);
blankView.setViewState(ViewState.INVISIBLE);
dialogContainer.addView(stockPicker);
}
}
You can try replacing your scrollView with a list view still and see if that fixes things. You can also try tweaking layout and gravity settings until you get it, or trying introducing other layouts or reorganizing your layouts (or using RelativeLayout, its really not that bad).

So, now in 2022 I've also had this problem. I've just set fixed size for ScrollView in fragment layout xml-file. When you have this problem, you can set, for example, 150dp or 200dp and be happy! And for more convenience, you can create special layout for landscape screen orientation and set fixed layout_height size there. I'm really confused that there's no information about this problem besides this page on the Internet.
<ScrollView
android:layout_width="match_parent"
android:layout_height="200dp">
<!--your view into scrollView here-->
</ScrollView>

Randomly place objects in an activity

So I'm new to java, and I have the basics of object placement down. I'm trying to design an app in which 5 objects are randomly placed in a certain activity. How would I go about randomly placing these objects?
Thanks!

Create a custom view that overrides the onDraw method.
Use Math.random or some other random number generating scheme to determine the x and y values of the bitmaps you are going to draw.
Then use Canvas.drawBitmap

you can programmatically add your buttons to your activity with random position without using xml layout and here an example set buttons in activity
LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.VERTICAL);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
Button okButton=new Button(this);
okButton.setText("some text");
Random r = new Random();
okButton.setPadding(r.nextInt(), r.nextInt(), r.nextInt(), r.nextInt())
ll.addView(okButton, layoutParams);
and here good thread to look at
Set margins in a LinearLayout programmatically

Android button with transperent png image and background colour

I need a button with foreground transparent image and background color. So have use this code. The background color is going outside of the image. I need the button with the same size of the image.
Depending on the user interaction i have to change the foreground image and background color. I want add the image and background color separately so that i can change one of them at minimum cost. I have to use a lot of button in this UI so it will be done in java code.
layout = new TableLayout(this);
layout.setLayoutParams(new TableLayout.LayoutParams(8,7));
TableRow row2 = new TableRow(this);
buttonPlayer1 = new ImageButton(this);
buttonPlayer1.setImageDrawable(getResources().getDrawable(R.drawable.blankc4));
buttonPlayer1.setBackgroundColor(Color.GREEN);
row2.addView(buttonPlayer1);
layout.addView(row2);

If your only problem is that button background color is going outsize image and you need button size to be same as image size then get image Height and Width using getHeight() & getWidth() methods on image object and use these values to make the Button size same as Image size using setHeight() & setWidth() methods respectively on button object.
Sample Code with LinearLayout:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout btnLO = new LinearLayout(this);
btnLO.setOrientation(LinearLayout.VERTICAL);
ImageButton i1 = new ImageButton(this);
i1.setBackgroundColor(color.background_dark);
i1.setImageDrawable(getResources().getDrawable(R.drawable.rana));
btnLO.addView(i1, new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));
// btnLO.setGravity(Gravity.LEFT | Gravity.CENTER_HORIZONTAL);
this.addContentView(btnLO, new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));
}