Develop Reference

GridView eats my onTouch events and starts "scrolling"

I am creating an android app in which I need to track the pointer on a couple of elements that are inside a GridView. The problem is that if the pointer moves a little bit up or down, the GridView enters some kind of scrolling mode (even if it fits easily inside the screen), so the events do not reach the child views anymore. Is there anything I can do to prevent this behaviour and keep tracking the pointer inside those children?
So to clarify: the pointer tracking works neatly, until the vertical difference between starting and current position becomes to large. At that moment, no touch event reaches my child elements anymore, and the gridView starts scrolling if it does not fit inside the screen.

I found a solution at another StackOverflow post. Simply put, the solution is to create a class that extends the GridView and overrides the onInterceptTouchEvent method, which must return false when scrolling (or any other form of interception) has to be prohibited.

Center aligned selection with animation in ListView (?)

I need a component that works like the picture below but I'm having trouble coming up with some kind of decent solution that works.
I want the list to have a center locked selection but being scrollable with the d-pad. This is for an application running on a TV so no need for touch scroll. So when pressing down on the remote d-pad the list will scroll and a new item will size up and the current selected one will size down and the new selection will still be in the middle.
I've tried doing this using a ListView that I extended and programmatically scrolling when pressing down or up. On scroll finished I called notifyDatasetChanged() on the ListView for re-inflating of the childs and in the ListViews adapters getView() I made the animation of the view located at the current selected position.
This is not optimal since I need to call notifyDatasetChanged(), which re-inflates all visible views, for the animation to apply. The UI becomes laggy when doing this and scrolling fast. It's also not possible to make som kind of compress animation when current selected item goes out of selection. There is also some trouble with the end items (read views) such the first or last in the list when doing animation of them, the may sometimes go out of screen.
I think that his must have been done before and maybe I'm missing it when searching for an answer.
Have anyone done something similar or do you have some suggestions of how this can be achieved? Maybe I'm just starting of with the wrong component here..
Regards,
Kristoffer

android drag and drop gridview ordering

I created a drag and drop gridview (using an OnDragListener). Grid items can be dropped upon one another. However, I also want to be able to re-order them. I implemented this, but there is a major issue left standing: the user control part.
When I drag around my shadow object I want the items to make space for my dragged object while I am dragging it around. I already implemented the moving of the other items, but I cannot seem to figure out a way to find out IF/WHEN I am in between two items. I get drag events when I hoover ABOVE an item, but not in between then. The gridview does not get any onTouchEvent calls when I am dragging, not even onInterceptTouchEvent calls.
Does anyone know a way in which I can implement this?
I already tried:
Implementing onTouchEvent and onInterceptTouchEvent in the gridview. Problem:
The gridview does not get any onTouchEvent calls when I am dragging an item, not even onInterceptTouchEvent calls.
Setting another draglistener on the whole gridview. Problem: ACTION_DRAG_LOCATION gets only called a few times, not on every move (location change), as is documented (!!).

I removed the padding between the grid items and gave the items themselfes some extra size, so that you are never inbetween items, but also on the side of one of the items. I detect when I'm at the side of an item and move the items accordingly to make space for my dragged item.

Gallery overlapping items click

I have a Gallery based View with a negative spacing between elements, so that one zoomed out behind the previous, i.e. 'carousel'. Zooming and carousel effect is achieved by Camera transformation.
The problem arises when I try to click right side of foreground item and what I really get is click on item behind it (always to right of it)
Let me enumerate what I've already tried:
setChildrenDrawingOrderEnabled(true);
z coordinate of background item is obviously greater then foreground
one
getChildDrawingOrder was overridden as many ways as possible (and I
found out that it doesn't play any role at all - touch events don't
depend on visibility order of views)
Seems like next(right) child has greater index and therefore a priority of handling UI events, and my z-coordinate/drawing order manipulations don't change anything.
So question: how to make foreground item responsible for all click events on it?

One touch event puts all child views into pressed state

Doubtless this is caused by my decidedly unorthodox layout - I have buttons in a LinearLayout in an Activity which is placed by an ActivityGroup into a Gallery. The ActivityGroup is also the adapter implementation and the over-all effect is full-screen sliding, snapping panels.
This is working (a treat, actually) except that a touch event on the parent layout puts all the buttons into the pressed state (and any release removes the state). A touch on an individual button is only delivered to that button.
The buttons are not receiving any events, they're only changing state.
Have I done something obviously wrong? Is this a known bug and is there a work-around?
Any insights would be very much appreciated.

As obscure as this problem is its solution may be of use to someone else, so I'll answer my own question.
As mentioned, I'm (mis)using the Gallery to provide a slidey-panel à la iPhone. I do this by returning the top level window of an Activity when the Gallery asks its Adapter implementation for a view.
Typical use of a Gallery would result in small Views to which it's desirable for the press event to be applied - it's more like a button then it is a panel. Our use means that there are many buttons in a single view and we don't want the press event to ever be applied globally.
So the work-around was very easy. I extended Gallery and deliberately broke pointToPosition(int x, int y), returning INVALID_POSITION every time. The Gallery still does everything else expected of it but skips trying to apply the touch down event to any elements but itself (to prepare itself to scroll or fling).
I hope this is of value to someone.