Develop Reference

Ideas how to build a screen with 100 Views added programatically

Right now I'm stuck how to manage to build a specific Activity in my app. I've added an image so I can explain my problem:
So first of all: all the content will be loaded from an API. "Static text" in my image means that I can define these parts in my activity.xml and don't have to do that in my Activity.java because these parts will be always the same for the screen (meaning the size of the elements, the content will be loaded from my API).
The green box should be horizontal scrollable or not depending how many boxes have to be shown here (1 to 3 possible).
The blue box will be generated in my Activity (in the end it should look like a table) and I want to define the layout of a single row in a separate xml (e.g. table_row.xml) so I could change it easily. This table can have up to 100 rows depending on how many are returned by the API.
So my problem right now is: Obviously this whole layout has to be scrollable so my first idea was to use ScrollView and a LinearLayout as child. But I read here on stackoverflow that the performance will be really poor if you use LinearLayout and add Views to it. So everyone recommended using a ListView for this part (meaning the blue box for my Activity). But that would mean only my blue box will be scrollable as you should not use a ListView in a ScrollView.
So my question is: How can I make this whole screen scrollable with a table dynamic in size without losing performance?

Put the first three layouts as ListView Header and make your blue box layout as the list view. By this you'll be able to scroll the complete View i.e. Blue Box, however the first three layouts will be static and won't scroll.

Android Drag-n-Drop grid with LinearLayouts as drag items

I have a working example of a grid that allows items to be reordered using long touches to active a drag-n-drop. All is working well if the items are simple Views e.g. TextView or ImageView but if the items are LinearLayouts only the layout itself is displayed.
I've been using Tom Quinsn's grid (thanks Tom!!!) from this posting:
Android Gridview drag and drop example
I can get LinearLayouts to work if I derive my own LinearLayout class and override onLayout(), but this forces me to hardcode the positions of the child controls in the layout within this function.
Ideally I would like to be able to define the item layout within an XML file and inflate them before adding them to the Control that handles the grid. I'm guessing that for some reason the framework is not calling the layout function for the children contained within the DraggableGridView view as defined in Tom's code but I can't understand why that is.

I am developing my own Drag and Drop app with good help from this link. You may compare the code with the one from Tom Quesinsn. It also gets the different children of a GridView and add them as "drop targets" that accepts drops on them and copy the Image of the View you are dragging.

This is a known problem with the DraggableGridView that -- unfortunately -- I haven't gotten around to fixing. When I wrote DGV, I didn't entirely grasp how views were laid out. You might try having DGV measure each child before laying it out. Adding something like:
getChildAt(i).measure(MeasureSpec.makeMeasureSpec(childSize, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(childSize, MeasureSpec.EXACTLY));
before the layout on this line:
getChildAt(i).layout(xy.x, xy.y, xy.x + childSize, xy.y + childSize);

Hiding the Header view in ListView

I'm trying to add a header view to my list, and hide it all the time unless we scroll to it (like the pull-to-refresh mechanism). The problem is: if the list is not tall enough to fill the screen - the header view is shown on top of the list.
Is there a way to hide it, and make it visible only when we scroll to it? I've been trying a lot of stuff, but I can't figure out a good and simple way to do so.
Thanks

Here's a blog post describing a simple way of hiding and showing the header view.
The idea is to to put the content you wish to hide in a LinearLayout that wraps it, and hiding the content only. That way, the wrapping LinearLayout will collapse when its content is hidden, resulting in a headerView that is technically still present, but 0dip high.
Note: If you would try to hide the content without the enclosing layout, you would be left with unwanted space in the header view.
An example layout with a spinner representing the content:
<LinearLayout
xmlns:a="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<ProgressBar
android:id="#+id/spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
Then you can hide the spinner (content) as follows:
spinnerLayout.findViewById(R.id.spinner).setVisibility(View.GONE);

You could look into ListView.setOverscrollHeader() or ListView.setOverscrollFooter(). Is this the behavior you are looking for?
If not, could you post some code showing what you have so far?
EDIT:
Ok so I looked into Overscrolling headers/footers and you're right, I don't think that's what you want at all.
Instead you should probably look into the Pull to Refresh mechanism from the Twitter app that others have tried to emulate. You can look into the answers from this question.
The most promising answer seems to be the custom ListView written by Johan Nilson, the code for which can be found here:
https://github.com/johannilsson/android-pulltorefresh
EDIT #2:
I took a look at the PullToRefresh custom ListView and what you want to do is probably possible, though not necessarily easy. Allow me to explain.
The PullToRefreshListView is essentially just a hack that exploits the optional Header in standard ListViews. The hidden "Pull To Refresh" that you see is really just the header of the ListView. When the list is displayed, this line is executed:
setSelection(1);
This scrolls the list to the first item on the list, effectively hiding the Header. When the List is short enough to be displayed entirely on screen, no scrolling is necessary, hence the "Tap to Refresh" button.
When this "Tap to Refresh" is visible, the pull to refresh mechanism is disabled, but it's easy enough to fix that. The pull to refresh effect is accomplished by increasing the top padding of the header view so that it appears that you are pulling the list down (when really it's more accurate to say that the Header is pushing the rest of the list down).
The amount of padding added is controlled by the applyHeaderPadding() function on line 199 of the source code. In that function there is an if statement on line 220 that only applies the padding when the list is in RELEASE_TO_REFRESH mode:
if (mRefreshState == RELEASE_TO_REFRESH)
{
//Some code that eventually adds padding to the header...
}
If you eliminate this condition or change it to apply padding no matter what mode you are in you can drag to refresh even if the list is short and the header says "Tap to Refresh"
if (true)
{
//Some code that eventually adds padding to the header...
}
However, this doesn't exactly create the effect you're looking for. If the list is short, you can drag it down to refresh, but the "Tap to Refresh" header is still shown. Now the problem is "How can I hide the header until the dragging motion begins?" This is a difficult problem on it's own, with several Stack Overflow questions dedicated to it.
If you want a header, you must add it BEFORE you set the adapter for the ListView, otherwise you get all sorts of errors.
I had some success with this, but I haven't come up with anything stable, because my solution is a kind of nasty hack on top of the already hacked PullToRefreshListView. I set an empty FrameLayout as the header and added the original pull to refresh header to that Frame Layout. Then, as I dragged the list, I edited the height in the LayoutParameters of the Frame Layout to grow and shrink much like the padding had originally. It sort of worked, but would eventually force close, and I haven't figured out why yet.
Anyway, if I get it to work I'll post the code, otherwise someone wiser than I might propose a solution based on the info I just provided.

Here is a solution for the current PullToRefreshListView (updated November 4, 2011):
https://github.com/johannilsson/android-pulltorefresh
based on the Hiding Header Views article:
http://pivotallabs.com/users/joe/blog/articles/1759-android-tidbits-6-22-2011-hiding-header-views
1) Copy pull_to_refresh_header.xml from the library's res/layout to your app's res/layout.
2) Edit your app's pull_to_refresh_header.xml. Wrap topmost RelativeLayout in a LinearLayout and then wrap the LinearLayout in a RelativeLayout again. Why? Topmost layout must be RelativeLayout because that's what's expected in code, second level layout must be LinearLayout because that's the only layout that collapses with View.GONE. Third level layout must be the same as original top-level RelativeLayout (except id) to preserve look.
3) Preserve same id on top RelativeLayout (pull_to_refresh_header), give second level LinearLayout an id of your choosing, give third level RelativeLayout another id (pull_to_refresh_header2 for example).
4) Move all padding from the topmost RelativeLayout to the second RelativeLayout.
5) In your code use findViewById and your LinearLayout id to set visibility to View.GONE. The LinearLayout will collapse, and if you moved all padding values appropriately to the inner RelativeLayout the header should take no space at all.

ANDROID, what layout elements should I use?

I need to make an android layout like this one.
tile background all over the screen.
top menu which, overlays the background ( note the shadow ).
some sort of a table with text options, maybe pictures, which can be scrolled up and down.
bottom menu, which appears by sliding up after a menu button is hit.
What kind of layout elements do you think I should use for that?
Thanks!

I think you should first learn about the Android Layout and XML layout design, then you can easily prepare this layout as well.
Relative Layout will be the better layout as compare to other layouts like Linear Layout and Table Layout.
To display middle part that is showing textual description may contains ListView (ListView because as you have mentioned Text Options should scroll up and down), but it depends on your requirement.

The RelativeLayout is the most flexible, and I think you can make all this with a minimal hierarchy view depth.

My approach would be to use a RelativeLayout. The Top Menu bar could be a custom class which extends a LinearLayout and this can be used in the RelativeLayout (in fact in any screen you have to provide UI consistency). Similarly, the bottom menu would be a custom control containing the appropriate animations. The rest of the screen would be contained in a ScrollView, possibly containing a TableLayout. I have something very similar using a MapView in the main screen and it works fine.

how to load part of the layout content alone

Friend's
I need help on loading the content alone in my page without going to new page when i selected the scroll menu.
**> I have an
1. header layout and
2. framelayout in another xml file have declared Listview and it
also have tabhost
**and also have gallery view for scroll menu.
3. content list in another xml file.****
when i selected the scroll menu i need to load the list content alone in that activity i suppose not to load whole header and and redeclare tabhost in next that scroll menu selected activity.
Thanks in advance.

I achieved this effect by having everything defined in a single xml file with multiple TableLayout views stacked on top of each other within a Merge view. In order to "load" a view, I change its Android:visibility tag from "gone" to "visible". Since you want your second view to not obscure the header, you can put a buffer (margin or padding) that offsets it from the top of the screen. The background color of this top TableLayout would have to be android:background="#00000000" so that the alpha channel is zero and it is transparent.
If anyone else has a more elegant approach, I would be interested to know as well, but this suites me just fine. The only downside I see is an extra large XML file.