What I am trying to do is programmatically creating a row of buttons with a constraint view.
I am creating two buttons and I want to have them next to each other without doing something to the .xml file, since the number of buttons can vary depending on the user.
I want to use something like (this code is part of an Activity):
ConstraintLayout layout = findViewById(R.id.layout);
Button btn1 = new Button(this);
Button btn2 = new Button(this);
ConstraintLayout.LayoutParams params1 = new ConstraintLayout.LayoutParams(ConstraintLayout.LayoutParams.WRAP_CONTENT,ConstraintLayout.LayoutParams.WRAP_CONTENT);
ConstraintLayout.LayoutParams params2 = new ConstraintLayout.LayoutParams(ConstraintLayout.LayoutParams.WRAP_CONTENT,ConstraintLayout.LayoutParams.WRAP_CONTENT);
layout.addView(btn1, 1, params1);
params2.topToTop = btn1.getId();
params2.leftToRight = btn1.getId();
layout.addView(btn2, 2, params2);
Setting the two params2 values does not work because apparently I cannot really access the ID of button1.
What would be a working solution to this?
Things I have read and tried:
Using tags instead of ids
Accessing the buttons using an ArrayList of all the created buttons as a private member for the Activity
Giving some random id (that I have chosen) to the Views using setId()
Using something like this works, because I have predefined that btn3 in the xml file:
params2.topToTop = layout.findViewById(R.id.btn3).getId();
params2.leftToRight = layout.findViewById(R.id.btn3).getId();
But in all the other cases my btn2 just lands on top of btn1 (or rather on the top left edge of the layout)
Thank you in advance!
You can use the following method to generate view id programmatically:
private static final AtomicInteger nextGeneratedId = new AtomicInteger(10000);
public static int generateViewId() {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
for (;;) {
final int result = nextGeneratedId.get();
// aapt-generated IDs have the high byte nonzero; clamp to the range under that.
int newValue = result + 1;
if (newValue > 0x00FFFFFF) newValue = 10000; // Roll over to 10000, not 0.
if (nextGeneratedId.compareAndSet(result, newValue)) {
return result;
}
}
} else {
return View.generateViewId();
}
}
call .setId(generatedId) for the buttons you create.
I am programming an app which generates all of its layout programmatically. I am looking to place an array of ImageView[] depending on their index. But it looks like the LayoutParams doesn't do anything since all the ImageViews are being superposed. Here is the code I am using:
for (int i=0; i<tiles; i++){
Log.i("Setting up tile", "#" + i);
tileParams.removeRule(RelativeLayout.ALIGN_PARENT_TOP);
tileParams.removeRule(RelativeLayout.ALIGN_PARENT_START);
tileParams.removeRule(RelativeLayout.BELOW);
tileParams.removeRule(RelativeLayout.RIGHT_OF);
if (((double)i/columns) == Math.round(i/columns)){
if (i == 0){
tileParams.addRule(RelativeLayout.ALIGN_PARENT_TOP);
tileParams.addRule(RelativeLayout.ALIGN_PARENT_START);
} else {
tileParams.addRule(RelativeLayout.BELOW, tileView[i-columns].getId());
tileParams.addRule(RelativeLayout.ALIGN_PARENT_START);
}
} else {
tileParams.addRule(RelativeLayout.RIGHT_OF, tileView[i-1].getId());
}
tileView[i].setLayoutParams(tileParams);
grid.addView(tileView[i]);
}
Here, "grid" is a RelativeLayout and "tileParams" is a RelativeLayout.LayoutParams.
PS: I know that the if
methods are used correctly at the required time, and the ImageViews have their ids set using iv.setId(View.generateViewId()).
I am creating an app where I will be loading some images and data from a database, it should look like this:
Image______Name of user
Image______Name of user
Image______Name of user
etc..
I tried to create it just with a dummy image and some text to figure out how it works.
I create a LinearLayout, ImageView and a TextView, I add those two to the LinearLayout, and than I add that LinearLayout to a RelativeLayout.
The problem is, that all the images and text are placed in the same place, on top of each other. How can I change it so it is in the format I need?
relativeLayout = (RelativeLayout) findViewById(R.id.rel);
for(int i = 0; i< 30; i++)
{
LinearLayout layout = new LinearLayout(this);
layout.setOrientation(LinearLayout.HORIZONTAL);
TextView hello = new TextView(this);
ImageView imageView = new ImageView(this);
imageView.setImageResource(R.mipmap.ic_launcher);
String hi = "Hey";
if(i == 0){hi = "Hello0";}
if(i == 2){hi = "Hello2";}
if(i == 3){hi = "Hello3";}
if(i == 4){hi = "Hello4";}
hello.setText(hi);
layout.addView(imageView);
layout.addView(hello);
relativeLayout.addView(layout);
}
I am using a for to loop it a few times just for test.
Instead of RecyclerView, add the items in a LinearLayout. You can also set position where to add the new item in the LinearLayout.
I would suggest you do instead is:
create a model object for the user details(name and picture)
Use ListView or RecyclerView with a simple adapter add items to an
ArrayList of model object and notify the adapter when data is
changed.
This way you'll be reusing the views, and that'll improve the performance much better.
for examples, you can take a look at these sample projects.
https://github.com/lokeshsaini94/SimpleAndroidExamples/tree/master/ListView
https://github.com/lokeshsaini94/SimpleAndroidExamples/tree/master/RecyclerView
I am developing an app that requires multiple buttons to be created dynamically (onCreate of MainActivity class). Each button has a dimension of 100x100dp.
Here's the code:
for (int i = 0; i < count; i++) {
buttons[i] = new Button(this);
RelativeLayout ll = (RelativeLayout)findViewById(R.id.maincontainer);
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
buttons[i].setY(i * 150); // should be random
buttons[i].setX(i * 120); // should be random
String temp = Character.toString(input.charAt(i));
buttons[i].setText(temp);
buttons[i].setOnClickListener(this);
buttons[i].setId(i);
test1.setText(Integer.toString(buttons[i].getId()));
ll.addView(buttons[i],lp);
}
The position of these buttons should be completely random within the layout which can be easily achieved by generating random values for x and y coordinates. But I need the buttons not to overlap other buttons. Also due to 100x100dp dimension, sometimes the previously generated buttons are being partially overlapped by new ones.
You can actually figure this out programatically. Keep the co-ordinates of the views that you generate stored in a list. Then simply compare the co-ordinates to see if the new view intersects. You can use the following for a visualisation:
http://silentmatt.com/rectangle-intersection/
I hope you try writing code than copying it from someplace. :)
A SO link to help you out: Determine if two rectangles overlap each other?
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>