Develop Reference

Webview scrolling on Android not working properly

In the webview.xml, I only have a frame layout as a wrapper for the webView as the following,
<FrameLayout
android:id="#+id/scroll_wrapper"
android:layout_width="match_parent"
android:layout_height="match_parent">
<WebView
android:id="#+id/web_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</FrameLayout>
As a little background of the webview, it's basically a mobile web page that displays pictures, and allows for horizontal scrolling(either swiping or clicking the 'next' button). Right now, I'm able to scroll to the next photo via swiping, but once I release my finger, the photo pops back to the original photo. Same thing is happening for clicking next, the screen displays half of the next photo before scrolling back to the previous photo.
I have absolutely no idea why this is happening as I've tried all options with playing with the horizontal scrolling attributes, but it still isn't working. Could anyone who has experienced this provide some insights. Please feel free to let me know what additional info you need.

try using linear layout rather than using frame layout as you have only one child that is webview for the parent layout.
this one works for me :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<WebView
android:id="#+id/webview_content"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" />
</LinearLayout>

Android fixed background image in scrollview while scrolling

I have a situation where I need a scrollview to have a background image that shouldn't scroll along with it's parent when moving. Before any of you suggest me the links for setting background image and this that, I have already tried and it's not working.
The whole story goes like: I have an activity with fragments which have their own backgrounds with some input fields. When focusing over input fields, keyboard appears and background image squeezes. For that I put an image on background of scrollview that fixed my issue of squeezing background but raised another concern that background Image should stay static while scrolling the parent scrollview.
The second solution any of you may suggest is setting background of my activity rather playing with scrollview. That's right, but for that I had to make a style element with background of theme which appears odd while transitioning different fragments plus it adds overhead when I have a lot of code and fragments to move forward and back.
That's the point where I am stuck. I have gone through links below, if you just need to know that I tried it or not.
link1
link2
link3
... and so on
below is the layout I am using for my fragments (it's all being done programmatically)
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/top_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<ScrollView
android:id="#+id/scrollView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true"
android:scrollbars="none" >
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<ImageView
android:id="#+id/backgroundView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:contentDescription="#string/app_name"
android:scaleType="fitXY" />
<LinearLayout
android:id="#+id/parent_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
</LinearLayout>
</FrameLayout>
</ScrollView>
</LinearLayout>
So if you guys have any better solution keeping in mind the situation I have, will be warmly welcomed. Thank you

None of the above works for me with some reason but this things works.
getWindow().setBackgroundDrawableResource(R.mipmap.img_reg_bg);
put it in oncreate method hope it will help.

If I guess right you try to fix your hotfix to get it working propperly. If I'm right you sould go back to scratch and do it without your scrollview.
If you have a look at following Link:
http://developer.android.com/guide/topics/manifest/activity-element.html#wsoft
you'll see softkeyboard mode can be adjusted. "adjustPan" should solve your problem.
"adjustPan"
The activity's main window is not resized to make room for the soft keyboard. Rather, the contents of the window are automatically panned so that the current focus is never obscured by the keyboard and users can always see what they are typing. This is generally less desirable than resizing, because the user may need to close the soft keyboard to get at and interact with obscured parts of the window.

Add someimgage to your drawable folderes, like drawable-mdpi, drawable-hdpi.
In your LinearLayout "#+id/top_layout" add attribute:
android:background="#drawable/someimage"

Android bringToFront GridView Issue

I'm developing an app which contains an image at the upper half of the screen and a gridview in the half below, like this:
<de.test.gridview.Image
android:id="#+id/image_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:fadingEdgeLength="0dp"
android:scrollbars="none"
android:visibility="gone" />
<de.test.gridview.DraggableGridView
android:id="#+id/grid_view1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/topnews_container"
android:background="#FFF"
android:gravity="center"
android:numColumns="auto_fit"
android:stretchMode="none"
android:tag="grid_view_tag" >
</de.test.gridview.DraggableGridView>
The Image is set to visibility=gone and set to visible in the code manually later on.
When I now drag on of the childs of the gridview I cant be able to drag them over the image in the upper half of the screen. They are always behind the image, but never in front of it. I've tried to use
gridView.bringToFront()
and also within the gridView I tried this function. I also tried this on the children of the gridview with gridView.bringChildToFront(child). But nothing worked.
Does anybody have an idea?

I guess view with property set to View.GONE is not operational via bringToFront(). So I believe the following will work (if you are trying to bring the grid to the front/top of z):
gridView.setVisibility(View.INVISIBLE);
gridView.bringToFront();
But its looks like you want to bring imageView to the front (making gridView behind instead of front). If so you need to:
imageView.setVisibility(View.INVISIBLE);
imageView.bringToFront();

fill_parent in LinearLayout isn't being honored

After much research on both SO and google, I haven't seen any one with exactly the same problem I am experiencing, so here it is:
I recently redid the entire UI on an android app. For the most part, I made only cosmetic changes to each of the screens. They appear in the UI editor of eclipse perfectly as expected. However, directly after doing this, two of the screens stopped being laid out correctly on both all tested devices and the emulator.
Now, the big problem one these two screens was that the root level LinearLayout didn't appear to be actually honoring the fill_parent for either layout_height or layout_width. it looks like it's being measured as if it were set to wrap_content instead. It only takes up about 70% of the screen - which is just enough to wrap the individual elements inside the root LinearLayout. I would post an image, but as a new user, I am not allowed to.
The layout isn't stretching to fill the screen. Here's the code for layout, except that there are a few more in the LinearLayouts containing a TextView and an EditText.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FF000000"
android:orientation="vertical" >
<TextView
style="#style/sans.white.16.bold"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingTop="4dp"
android:text="#string/edit_account" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<com.teamunify.ondeck.widget.TUTextView
style="#style/sans.white.14"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:text="#string/first_name" />
<com.teamunify.ondeck.widget.TUEditText
android:id="#+id/acc_editor_first"
android:layout_width="fill_parent"
android:layout_height="40dp"
android:selectAllOnFocus="true"
android:singleLine="true" />
</LinearLayout>
I think the root LinearLayout should be filling both height and width. I've used this same layout many MANY times in our app without problems. (A quick count revealed that I used 76 LinearLayouts in our app, and all but two of them are working.)
At first, I suspected that perhaps our custom classes measure was wrecking things, so I changed the layout to use all plain EditTexts, but there was no change. I double checked the activity, but it isn't doing anything except to load this xml. So, in desperation, I redid the layout like so:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FF000000"
android:orientation="vertical" >
<TextView
style="#style/sans.white.16.bold"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center|top"
android:paddingTop="4dp"
android:text="#string/edit_account" />
</LinearLayout>
After that, The words Edit Account appear with a black background mashed into the upper left corner. Clearly, the LinearLayout isn't filling the parent.
Long story short, I am asking how to fix this so that the LinearLayout fills the screen as expected.
I am at a complete loss as to why this is happening, and I am certainly hoping that someone on SO has an idea. This has got me pulling my hair out!

Try setting fixed width and height for the root layout.
Then only you will be able to debug who is driving length and width. It is very much possible that parent activity or background activity is setting dimensions. Once you identify the root cause you can go back to original settings.
As of now from your code snippet given here, nothing wrong here

If you use a custom activity as a container to other activities for some reason (In our case, we were recreating the look of our iOS app, and needed a custom menu to show up along the button side of the screen) the window manager seems to get a bit confused with what the actual height and width of the nested activities should be. A call to fillparent or matchparent ends up wrapping the content instead.
We ended up changing the behavior of several methods in our container activity class to make this work.

Overlapping Views in Android

Is it possible to have overlapping views in Android? I would like to have an ImageView with a transparent png in the front and another view in the background.
edit:
This is what I have at the moment, the problem is that the image in the imageView is not transparent, the parts that should be transparent are just black.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/gallerylayout"
>
<Gallery android:id="#+id/overview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<ImageView android:id="#+id/navigmaske"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:src="#drawable/navigmask"
/>
</RelativeLayout>
edit:
I got it to work, it was a theme file from another programmer on the team.
Just changed this
<item name="android:background">#FF000000</item>
to this
<item name="android:background">#00000000</item>

Android handles transparency across views and drawables (including PNG images) natively, so the scenario you describe (a partially transparent ImageView in front of a Gallery) is certainly possible.
If you're having problems it may be related to either the layout or your image. I've replicated the layout you describe and successfully achieved the effect you're after. Here's the exact layout I used.
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/gallerylayout"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Gallery
android:id="#+id/overview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<ImageView
android:id="#+id/navigmaske"
android:background="#0000"
android:src="#drawable/navigmask"
android:scaleType="fitXY"
android:layout_alignTop="#id/overview"
android:layout_alignBottom="#id/overview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</RelativeLayout>
Note that I've changed the parent RelativeLayout to a height and width of fill_parent as is generally what you want for a main Activity. Then I've aligned the top and bottom of the ImageView to the top and bottom of the Gallery to ensure it's centered in front of it.
I've also explicitly set the background of the ImageView to be transparent.
As for the image drawable itself, if you put the PNG file somewhere for me to look at I can use it in my project and see if it's responsible.

Also, take a look at FrameLayout, that's how the Camera's Gallery application implements the Zoom buttons overlay.

If you want to add your custom Overlay screen on Layout, you can create a Custom Linear Layout and get control of drawing and key events. You can my tutorial- Overlay on Android Layout-
http://prasanta-paul.blogspot.com/2010/08/overlay-on-android-layout.html

The simples way arround is to put -40dp margin at the buttom of the top imageview

A visible gallery changes visibility which is how you get the gallery over other view overlaps. the Home sample app has some good examples of this technique.

Now with Jetpack Compose in android, you should use Box for overlapping views.
Example.
Box(modifier = Modifier.fillMaxWidth().fillMaxHeight()){
RecipesList(viewModel.recipes.value)
Snackbar()
}
Here RecipesList and Snackbar are composabes positioned one on top of the other in the composition order
Check out this for Jetpack Compose samples - https://androidlearnersite.wordpress.com/2021/08/03/jetpack-compose-1-0-0-sample-codes/

Yes, that is possible. The challenge, however, is to do their layout properly. The easiest way to do it would be to have an AbsoluteLayout and then put the two images where you want them to be. You don't need to do anything special for the transparent png except having it added later to the layout.