How to wrap content views rather than background drawable? - android

How can I get a LinearLayout (or any other ViewGroup) to assume the size of it's child views rather than assuming the size of the background image?
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/large_image300x300pix">
<TextView android:id="#+id/TextView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello world!"/>
</LinearLayout>
The linear layout becomes the same size as the background image.
How can I get my linear layout to assume the same size as the textview?

OK, so this thread is a little old, but I have a solution that someone might someday find useful. I think Android has problems scaling large images down, so the LinearLayout size ends up getting bumped by the background drawable bitmap, and the ImageView ends up forcing up the size of the parent container.
Unless you use a relative layout. You can make the ImageView relative to the position of the LinearLayout, even when the ImageView is behind the layout in the parent. My solution looks something like this:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android">
<ImageView
android:src="#drawable/activation_popup"
android:scaleType="fitXY"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_alignTop="#+id/activation_layout"
android:layout_alignBottom="#id/activation_layout"
android:layout_alignLeft="#id/activation_layout"
android:layout_alignRight="#id/activation_layout"
android:contentDescription="#string/act_code_label" />
<LinearLayout
android:id="#id/activation_layout"
android:clipToPadding="true"
android:padding="25dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" >
<!-- LinearLayout wraps a bunch of smallish views here -->
</LinearLayout>
</RelativeLayout>
I tried this on a top of display sizes and OS versions, seems to work great. Note that the padding in the LinearLayout is a trick to make space for a shadow border in the background image graphic. The LinearLayout doesn't need any relative positioning because top left is assumed.

You can create a FrameLayout and put an ImageView and your LinearLayout there. So you'll be able to configure the layout of your background image.

This happens because the Android view calculates its minimum size based on its background drawable size.
Check my answer here in this another post which covers the same problem which will help you to achieve your layout configuration.

If your image lends itself to being converted to a scalable 9-patch image, then doing that would cause the background to scale around the TextView.

I believe the best solution here is to set android:clipToPadding="true". What this does is excludes the padding for the main layout and wraps your layout to its children.

Related

Android overlay outside/between layout boundaries

I have to add an overlay (ImageView) so that it's a bit shifted to the left of the containing layout's left boundary.
What is the best way to do this?
Tried something simple, like putting the ImageView inside the layout and use negative margin
android:layout_marginLeft="-20dip"
This made this:
(Correction: Text in the image should be 20dip not 20px)
AbsoluteLayout is deprecated. Is there something like z-order? Or what do I do?
Thanks in advance.
Edit: I tried using relative layout instead. Same effect. Here's the xml reduced to a minimum:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:clipChildren="false"
android:paddingLeft="50dip"
>
<ImageView
android:id="#+id/myId"
android:layout_width="60dip"
android:layout_height="60dip"
android:layout_marginLeft="-30dip"
android:clipChildren="false"
android:src="#drawable/pic" />
</RelativeLayout>
Result
Also happens when the containing layout has a background image smaller than the screen instead of padding.
Using RelativeLayout instead of LinearLayout (to allow overlapping) and adding this to the RelativeLayout fixed it:
android:clipToPadding="false"
set "android:clipChildren = false" in xml
Instead of
android:layout_marginLeft="-30dip"
try with
android:paddingLeft="-30dp"
Use a transparent(android:background="#00000000") imageview to the left of linear layout with width = 30dp. And make myId as aligning left in case of relative layout. If you are using linear layout make orientation as horizontal and let the transparent imageview be the first entry in it.

Android horizontal LinearLayout with wrapped text in TextView

I've observed a behavior with layout_weight that I can't explain. The following is a trivial example:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:text="This is a very very very very very very very very very very very very very very very long string."
android:layout_weight="1"
/>
<View
android:layout_width="32dp"
android:layout_height="32dp"
android:layout_gravity="center_vertical"
android:background="#ffffffff"
/>
</LinearLayout>
In a QVGA display, the TextView wraps the text. The white square is displayed to the right of the text.
However, if I remove android:layout_weight="1" from the TextView, the TextView now takes up the entire display width. The white square is no longer displayed.
Why would layout_weight in the TextView affect whether or not the white square is displayed? Shouldn't the View with the white background always be assigned 32dpx32dp first? (It makes no difference if the view were any other types - ImageView or TextView).
The problem I was working on is that I want the white square to always be displayed to the right of the TextView (whether or not the text is wrapped), but I don't want any empty space between the TextView and the white square. (If I add android:layout_weight="1" to the TextView, then there is a gap if the text is not wrapped.)
Any help would be appreciated!
To answer my question #1: One thing I learned by looking at the source for LinearLayout: Not only does layout_weight assign unused space to a child, it also shrinks a child with layout_weight if the child extends beyond the bounds of the LinearLayout. That explains why a TextView with wrapped text is shrunk in my layout.
As for the answer to my question #2, I think you meant android:toRigthOf instead of android:layout_alignRight. Using a RelativeLayout instead of a LinearLayout doesn't change the layout behavior. The tricky part is placing a view immediately to the right of a TextView, without gaps, whether or not the text is wrapped. Setting a maxWidth would limit the TextView's width, but that solution doesn't scale across portrait/landscape and different display dimensions.
Solution - Looks like Dyarish's solution is the best available. My layout problem exists regardless of the layout you use. The key is to set a maxWidth for the TextView so that it doesn't take up the all of the horizontal space in the layout. Because hardcoding a android:maxWidth value in the TextView doesn't scale across different displays, setting the maxWidth at runtime, as Dyarish suggested, is a good solution.
Hopefully this is what you are looking for.
First off, here is a great resource I found for Creating UI's.
layout_weight - Specifies how much of the extra space in the layout to be allocated to the View.
If you want to ensure that the white square is always to the right of the textview, you can use a Relative View, and add the parameter to the view. android:layout_alignRight="+id#yourTextViewID". This should always make the box appear right beside the textView area. You should probably also add something like android:maxWidth="250px" This will ensure that you don't push the white box completely out of the screen.
Here is a code sample:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<TextView
android:layout_width="wrap_content"
android:maxWidth="250px"
android:id="#+id/TextForWhiteBox"
android:layout_height="wrap_content"
android:layout_gravity="center|left"
android:text="This is a very very very very very very very very very very very very very very very long string."
/>
<View android:background="#ffffffff" android:layout_width="32dp" android:layout_height="32dp" android:id="#+id/view1" android:layout_toRightOf="#+id/TextForWhiteBox"></View>
</RelativeLayout>
You could also add to the View:
android:layout_alignTop="#+id/TextForWhiteBox" android:layout_alignBottom="#+id/TextForWhiteBox"
to make the white box the same size as the TextView.
Firstly I've tested the code from my other answer and it does exactly what you've described you've wanted. (unless I'm misunderstanding what you are asking for). You definitely do not want to use the android:layout_alignRight which is not what is in the code sample. That would simply keep the box on the right hand of the screen and not be affected by the textview at all. This sample uses android:layout_toRightOf="#+id/TextForWhiteBox" which is possible due to it being a relative layout. Since the Relative Layout allows you to place objects in relation to others. That line will always place the box just to the right of the textview with no gaps.
As for the screen orientation changes:
When the orientation changes it creates a new instance of the view.
Here is a simple solution.
//Add to oncreate in your Activity
private TextView textStatus;
textStatus = (TextView) findViewById(R.id.TextForWhiteBox);
// This get's the width of your display.
DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int width = displaymetrics.widthPixels;
// Now you know the screen orientation, and it's width. So just set the maxwidth of the text view to match the display width - the pixels of your white box.
textStatus.setMaxWidth(width - 32); // 32 is here because you already know the size of the white box. More logic is needed to dynamically get this value, because you would need to wait for the activity to be fully created.
}
Here is the main.xml I used:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<TextView
android:layout_width="wrap_content"
android:id="#+id/TextForWhiteBox"
android:layout_height="wrap_content"
android:layout_gravity="center|left"
android:text="This is a very very very very very very very very very very very very very very very very very very very long string."
/>
<View android:background="#ffffffff" android:layout_width="32px" android:layout_height="32px" android:id="#+id/view1" android:layout_toRightOf="#+id/TextForWhiteBox"></View>
</RelativeLayout>
You might need some additional logic to keep screen values.
This code has been tested, you should be able to literally copy and paste this to work as you asked.
Also depending on your logic you could use something like this to return the screen orientation.
int orient = getResources().getConfiguration().orientation;
Hope this helps!
If this helped you, please click the accepted button. =) Cheers!

Android crop background

I have a LinearLayout with width set to fill_parent and height to wrap_content. Now I want to give it a background from a png file, but doing it in a traditional way causes the LinearLayout to resize in order to show the whole background instead of cropping the additional part.
How can I set the background of LinearLayout so it won't resize?
Thanks
It appears that such thing is achievable only using the ImageView and setting the scaleType parameter accordingly. A quick workaround is to use FrameLayout and put the ImageView under another layout with transparent background.
Code:
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/imageView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:src="#drawable/background" />
</FrameLayout>
The default behaviour of background bitmaps is to fill the container completely and grow the horizontal and vertical size of the container if needed. The solution is to create a drawable bitmap resource and changing the gravity.
Check the following link and look for the possible gravity values. Your view should then just reference the drawable resource and you should be fine.
http://developer.android.com/guide/topics/resources/drawable-resource.html#Bitmap
I solved this one by subclassing LinearLayout and overriding the onMeasure(int,int) callback, then updating the layout XML to use my new layout type. I'm not at liberty to post that exact code, but what I did was invoke the super.onMeasure(int,int) implementation and check whether the measured height came back as the exact height of my background image. If so, I grab the measured height of all child views, then calculate a new height value and pass it to setMeasuredDimension(int,int).
put this code in the xml activity, for example activity_main.xml
<ImageView
android:id="#+id/imageView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:src="#drawable/image" />

Overlap views in android?

I have a linearlayout which have a textbox(multiline, nearly 5 lines) and image view. Is it possible to draw a image on textview(overlapping)?
Note: I have to specify the coordinates of the image, which are not static, and may be anywhere above text.
Something like this mockup:
I think it can be achieved using RelativeLayout.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<TextView
android:id="#+id/Textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:text="#string/Text2display"
android:textColor="#EEDCAA" />
<ImageView
android:id="#+id/choose_img"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="-46dp"
android:adjustViewBounds="true"
android:contentDescription="#string/description_logo"
android:src="#drawable/user2" />
</RelativeLayout>
By placing the TextView block above the ImageView, it ensures that the image view overlaps the TextView. Now, based on your requirements and position, use the following commands from the link :-
http://developer.android.com/reference/android/widget/RelativeLayout.LayoutParams.html
You can align left right, top and bottom. Use negative values to navigate the ImageView, if ur using align bottom and stuff.. This will make it to overlap. Please let me know if this was helpful
Is there any specific reason for Linear Layout?
You can do this easily using RelativeLayout . You can have an ImageView overlapping TextView Unless there is a specific reason for using LinearLayout .
If you really (really) need to use LinearLayout, you can subclass TextView and override onDraw to draw your image.
In all your xml files, should define the background color for it, it will solve the problem :
Add this android:background="#android:color/black" in to the View tag you defined.

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.

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