setFocus() causing two pushes to select imageview

Question

I'm developing a game Android app and I have a HorizontalScrollView that is being populated with ImageViews. Each ImageView is clickable to select the level you want to play. I'm using a SavedPreference to keep track of the last played level, and using that to determine which image is on screen when you load the menu. That way, if you're on level 30, you don't have to scroll all the way from level 1 every time.

I'm using a requestFocus() to bring that ImageView onto the screen, and it works fine, except for two relatively minor (but annoying) issues.

Here is what I'm doing in my for loop that populates the { HorizontalScrollView`:

        final ImageView iv = new ImageView(LevelSelect.this);
        iv.setImageResource(levelImages[i]);
        iv.setFocusable(true);
        iv.setFocusableInTouchMode(true);
        iv.setId(i);
        LinearLayout ll= (LinearLayout)findViewById(R.id.levelSelectGallery);
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(300, LinearLayout.LayoutParams.MATCH_PARENT);

and I make it clickable:

       String str = getString(R.string.level) + i + getString(R.string.avail);
       if (storage.getBoolean(str,false)) { //check if level is available (unlocked)
       iv.setClickable(true);
       final int finalI = i;
       iv.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               editor.putInt(getString(R.string.Current_Level_savepreferences), finalI); //set current level to clicked image
               Intent intent = new Intent(LevelSelect.this, LevelStart.class);
               LevelSelect.this.startActivity(intent); // begin LevelStart activity
           }
       });
       } else {
           iv.setImageResource(lockedImages[i]); // show locked image
       }

and outside the loop, I set the focus:

 //check if there is a saved level
 focusLevel = storage.getInt(getString(R.string.Saved_Level), 5); 
 //set focus on saved level
 findViewById(focusLevel).requestFocus();

This brings the focused item onto the screen, but just at the edge. I would prefer it to be centered if possible. I can live with that though. The main issue is that it seems that by setting the focus, it's now requiring two presses on the image to trigger the onClickListener. I assume the first press is changing the focus and the second is clicking. If I remove the focus related code, it only requires one press.

Is there a better way to scroll the view to the desired image, or something different I should be doing with the focusing?

score 0 · Answer 1 · answered Jan 26 '15 at 19:14

0

Why don't you just put focusLevel inside the onClickListener? That way tapping the image focuses it automatically.

answered Jan 26 '15 at 19:14

Ethan

225
2
13

The onClickListener is inside a for loop, as it is created for each ImageView that is being created in the loop. Wouldn't adding the focusLevel inside the loop create it for every image? Also, tapping the image already focuses it. But I don't really need it to be focused anyway. I was just using the requestFocus to scroll the HorizontalScrollView to the desired image. – Scott Strosahl Jan 26 '15 at 21:06
That's right, it probably would. Sorry Scott, I'm not sure then – Ethan Jan 26 '15 at 22:22

score 0 · Answer 2 · edited May 23 '17 at 11:49

So, I haven't found a way around the double press issue when the item is focused, but I did discover a different solution that works for my situation. Instead of using the HorizontalScrollView with a LinearLayout, I've now implemented a ViewPager which centers my ImageViews for me, and also allows me to scroll to an item programatically using setCurrentItem(). I don't have to use focusing at all.

For anyone looking to do the same, Philipp's example here helped me a lot: How to implement a ViewPager with different Fragments / Layouts

setFocus() causing two pushes to select imageview

2 Answers2