Develop Reference

How to use two views inside scrollview, ImageView below Constraint Layout

I have this ScrollView Which contains a ConstraintLayout with wrap_content height
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:ignore="ContentDescription">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
----------------
----------------
----------------
----------------
</androidx.constraintlayout.widget.ConstraintLayout>
</ScrollView>
Currently I am having one ImageView inside ConstraintLayout. which comes at the Bottom when I get the data from server.
But When I am in processing state , I see the image in the middle of the screen. That I want show at the bottom.
I want to place the ImageView at the bottom in such a manner that after getting data from server, it should come at the last after scrolling the screen and in the processing state It should be seen at the bottom.

try to set android:fillViewport="true" for ScrollView. this will make child of ScrollView (in your case ConstraintLayout) fulfil height of ScrollView in case when it have smaller height (so probably when you have only one ImageView inside). for testing just set some fixed color background for ConstraintLayout and check with and without this flag (by default its false)

RelativeLayout takes all its space, even though I've set its height to "wrap_content"

Background
I have a RelativeLayout inside a FrameLayout/RelativeLayout (doesn't matter to me), which should be at the bottom of the screen (like a toolbar), and should hold a few views in it.
Its height is set to "wrap_content" and so does its child-views.
The child-views of this layout are : A textView that is on the left, and a Horizontal LinearLayout on the right with a few buttons.
The problem
It seems that no matter what I do, the textview is causing the RelativeLayout to take the whole space, instead of just its children.
The code
Here's the minimal XML content that causes this problem. I've removed the extra stuff (LinearLayout and its children, and also some attributes that don't matter) since they don't cause this problem in case I remove the TextView:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FF000000" >
<!-- Here I've put some views that don't have any relation with the views below, so it doesn't have anything with do with the problem -->
<RelativeLayout
android:id="#+id/RelativeLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:background="#drawable/vertical_gradient_transparent_to_black" >
<!-- Here I've put a LinearLayout that doesn't cause the problem, so I've removed it for simplicity-->
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"/>
</RelativeLayout>
</RelativeLayout>
I've tried many possible attributes, and also tried adding additional layouts to try to "fool" the RelativeLayout, but none of those have succeeded.
The question
Why does it occur?
A working solution would be to use a Horizontal LinearLayout (with a weight for the TextView ) instead RelativeLayout , but I still want to know why can't I use a RelativeLayout, and why it occurs. Also how to fix it while still using RelativeLayout.

From the RelativeLayout doc:
Class Overview
A Layout where the positions of the children can be described in relation to each other or to the parent.
Note that you cannot have a circular dependency between the size of the RelativeLayout and the position of its children. For example, you cannot have a RelativeLayout whose height is set to WRAP_CONTENT and a child set to ALIGN_PARENT_BOTTOM
Class documentation
Which is exactly your case. RelativeLayout can not do that.

I have encountered the same issue before, this might be caused by android:layout_alignParentBottom attribute.Maybe you can find another way to achieve your desired effect. See this for more information.

This is some kind of Strange issue. Maybe someone else has the explanation.
I found it working when i removed the line
android:layout_alignParentBottom="true"/>
and it also worked when i tried some like this
<TextView
android:layout_width="match_parent"
android:layout_alignParentTop="true"
android:layout_height="wrap_content"/>

Android: How to apply LayoutParams to my RelativeLayout

I'm having difficult with this bit of code:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
RelativeLayout layout = (RelativeLayout)findViewById(R.id.RelativeLayout1);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
I have my RelativeLayout1 in xml like this:
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/ScrollView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/RelativeLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:paddingLeft="60dp"
android:paddingTop="53dp" >
But when I apply the scrollview, the fill_parent for RelativeLayout1 does not work as it should when it is not a child of scrollview. When it is not a child (i.e. I remove scrollview completely) then the relative layout covers the whole screen as I like it to. But when I put it inside scrollview, it only reaches the last element (a button) inside the relativelayout even though I use fill_parent.
So I am trying it programmatically to see if it makes a difference, but I can't seem to figure out how to apply my params variable to my layout one in the first bit of code. If you have any other ideas, do let me know as well.

You have forgotten to call the setter method layout.setLayoutParams(params).
To apply your created parameters you have to give them to the actual layout.
Be cautious with using fill_parent when the parent is a ScrollView. As the Scroll view adapts its size to its children.

I figured out how to solve my problem by adding a field to the scrollview and not doing this programmatically. In the ScrollView, I had to set the following:
android:fillViewport="true"

Add the attribute android:fillViewport="true" to your ScrollView if you want the RelativeLayout to fill up the ScrollView.
See Romain Guy's post about the same here: ScrollView's handy trick

Android RelativeLayout and height of wrap_content?

I am trying to make a selection ListActivity, similar to the one used to add shortcuts to the launcher screens. I have rolled my own header and footers, which I would like to be "sticky" at the top and bottom of the view when on screen. In order to do this, I am using a RelativeLayout with the header set to dock to top, footer set to dock to bottom, and the list set to go below the header and above the footer. In terms of the overall layout of the activity, this is rendering as I would expect. The header is sticky to the top, the footer is sticky to the bottom, and the list scrolls in between them.
One odd thing though happened when I switched to the RelativeLayout as my root. Please see the following screenshot:
I want my Activity's height to be wrap_content, so that the form is only as high as the content displayed in it, but once i switched to RelativeLayout, it seems to render the Activity effectively as fill_parent, taking up the whole screen, even though the content doesn't warrant it. Notice that there are not enough list items to fill the screen, which with the fill_parent style, is leaving a bunch of whitespace between the end of the list, and the footer. I was setting my height's via styles - which worked fine with LinearLayout, but seems to be ignored now. So I tried hard-coding the height directly on the RelativeLayout, but it still doesn't work and still renders as fill_parent.
Here is my layout code:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
style="#style/GroupsList"
android:layout_height="wrap_content">
<FrameLayout android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:id="#+id/hdrGroups"
android:layout_alignParentTop="true">
<include layout="#layout/title"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
</include>
</FrameLayout>
<FrameLayout style="#style/MyFooter"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:layout_alignParentBottom="true"
android:id="#+id/ftrGroups">
<ImageView style="#style/CloseButton"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:src="#drawable/add"
android:id="#+id/imgGroupsAdd"
android:clickable="true">
</ImageView>
</FrameLayout>
<ListView android:divider="#9f9f9f"
android:id="#+id/android:list"
android:choiceMode="singleChoice"
android:dividerHeight="1dp"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:layout_below="#id/hdrGroups"
android:layout_above="#id/ftrGroups">
</ListView>
<TextView android:text="#string/browser_no_groups"
style="#style/ListedItemB"
android:id="#+id/android:empty"
android:layout_height="wrap_content"
android:layout_above="#id/ftrGroups"
android:layout_below="#id/hdrGroups"
android:layout_width="fill_parent">
</TextView>
</RelativeLayout>
All layout is done via XML, ... I am not doing any layout in code.
How can I get the sticky header and footer while also having the activity as a whole behave in a wrap_content mode for its height? Is there some other way I should be going about this instead of a RelativeLayout?

According to the developer documentation your desired behaviour is not possible for Relative layout ;
"Note that you cannot have a circular dependency between the size of
the RelativeLayout and the position of its children. For example, you
cannot have a RelativeLayout whose height is set to WRAP_CONTENT and a
child set to ALIGN_PARENT_BOTTOM."
RelativeLayout
To solve your problem you could maybe try to use a linear layout, set to wrap_content and set max height via code to screen height.
You can get the screen height as described here : get screen height

I just change my RelativeLayout in FrameLayout and all starts to work

android: how to make a child view overlap the parent?

I need to implement the layout as in the picture. Parent and Sibling are in a vertical LinearLayout. So I need to make a child view to overlap it's parent. Can I do that in android?

If:
sibling is a sibling of parent
parent is a ViewGroup
and you really want child to be a child of parent
then maybe you could consider using android:clipChildren set to false on parent.

I was actually just looking at an example of a FrameLayout that had a TextView overlaid on top of an ImageView. So, there are obviously multiple ways to get it done. Your next question might be which one is best ... to that I have no idea, but here's a guy that might:
http://www.curious-creature.org/2009/03/01/android-layout-tricks-3-optimize-part-1/

Just contain them all within a RelativeLayout, and remember the draw order is top to bottom, so put the top most view on the bottom of the XML definition.

If you use a RelativeLayout you should have no problem achieving this effect. By default it will stack all of its children on top of each other in the top left corner if you don't supply them with android:layout parameters. So it will definitely support overlapping children. You'd just have to figure out what the best way to tell it where the child should go on the screen relative to something else.

There are at least two layouts that can do that. AbsoluteLayout and RelativeLayout. I suggest that you put your views in a RelativeLayout and add them with LayoutParams that specify their offset form the top and left of the parent:
RelativeLayout.LayoutParams rlp;
label = new TextView(ctx);
label.setBackgroundColor(0x00000000);
label.setTextColor(0xFF7ea6cf);
label.setTextSize(13);
label.setGravity(Gravity.LEFT);
label.setText("Examples:\n- Fentanyl\n- Dilaudid 2 mg PO q 4 hours prn moderate pain");
rlp = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT,100);
rlp.topMargin=189;
rlp.leftMargin=30;
rlp.rightMargin=30;
rlParent.addView(label,rlp);

In my case, I have to set android:clipCildren to be false on the parent of parent.
i.e.
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipChildren="false"
android:id="#+id/parent1">
<FrameLayout
android:id="#+id/parent2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="64dp"
android:background="#android:color/holo_blue_bright">
<View
android:id="#+id/This_is_the_view_I_want_to_overlap_parent2"
android:layout_width="160dp"
android:layout_height="80dp"
android:layout_gravity="top|start"
android:layout_marginTop="-40dp"
android:background="#000000" />
</FrameLayout>
</FrameLayout>