Develop Reference

How to make placeholder for RecyclerView that takes up rest of vertical space?

I am currently making a RecyclerView with 1 header section and n content sections.
__________________
| HEADER |
|----------------|
| CONTENT_1 |
|----------------|
| CONTENT_2 |
|----------------|
| |
| |
| |
|________________|
However sometimes, I don't have any content and I want to display a message saying "Sorry, you don't have any content right now" - or something like that. But I want that message to be centered in the remaining space.
__________________
| HEADER |
|----------------|
| |
| |
| |
| NO_CONTENT_MSG |
| |
| |
| |
|________________|
How would I go about achieving something like this? I can't seem to figure it out and so right now I am currently just using a fixed height placeholder message - something that I would rather not have.
__________________
| HEADER |
|----------------|
| NO_CONTENT_MSG |
|----------------|
| |
| |
| |
| |
| |
|________________|

Create something like
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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"
android:focusableInTouchMode="true"
tools:layout_editor_absoluteX="0dp"
tools:layout_editor_absoluteY="81dp">
<TextView
android:id="#+id/infotv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:text="No content here"
android:textSize="25sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
<android.support.v7.widget.RecyclerView
android:id="#+id/newsA"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
>
</android.support.v7.widget.RecyclerView>
</android.support.constraint.ConstraintLayout>
After that in your code, if you have content
infoTV.setVisibility(View.INVISIBLE);
And if you don`t have content
infoTV.setVisibility(View.VISIBLE);

Views with the same width and height

Is there a simple way to create xml layout like this below in android studio? I'm the iOS XCode guy and its no problem to do this there using ratio constraints.
So far I'm using ConstraintLayout and vertical gridlines with percent option. But this only gives me equal widths view1 and view2 and no height.
I know about overriding onMeasure method solution, but I want to avoid it.
a
---------------------------
| |
| |
| |
| |
| b b |
| ----------- ----------- |
| | view1 | | view2 | |
| |b | |b | |
| | | | | |
| ----------- ----------- |
---------------------------
b = 50% * a;

You can do something like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:orientation="horizontal">
<ImageView
android:id="#+id/imageview1"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content" />
<ImageView
android:id="#+id/imageview2"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content" />
</LinearLayout>
</RelativeLayout>
Now, in your activity or fragment, you get 2 views with findViewById();
And then:
ImageView view_instance1 = (ImageView)findViewById(R.id.imageView1);
ImageView view_instance2 = (ImageView)findViewById(R.id.imageView2);
LinearLayout.LayoutParams params=(LinearLayout.LayoutParams)view_instance1 .getLayoutParams();
params.height= params.width;
view_instance1 .setLayoutParams(params);
view_instance2 .setLayoutParams(params);

Android: horizontal gap between linear layout

I am new to Android & this excellent Question / answers site..
Currently i am facing a problem with gap / space between inner linear layouts.
I have multiple linear layouts nested (linear layout -> scrollview layout -> multiple Linear Layout).
My objective is to display ImageView (with images) sizes to change dynamically based on device screen resolution.
Each inner layout is having ImageView controls. I wrote to resize each ImageView to fit on screen at run time. At design time inner linear layouts are displayed without horizontal gap, but at rum time due to dynamic code they is a gap between linear layouts.
Design display
____________ ____________
| | | |
| | | |
| ICON - 1 | | ICON - 2 |
| | | |
____________ ____________
NO horizontal space
____________ ____________
| | | |
| | | |
| ICON - 3 | | ICON - 4 |
| | | |
____________ ____________
Runtime display
____________ ____________
| | | |
| | | |
| ICON - 1 | | ICON - 2 |
| | | |
____________ ____________
un wanted horizontal space
____________ ____________
| | | |
| | | |
| ICON - 3 | | ICON - 4 |
| | | |
____________ ____________
main.xml code
<LinearLayout
android:background="#drawable/llrightborder"
android:id="#+id/mainlayoutLeft"
android:layout_width="0dip"
android:layout_height="match_parent"
android:layout_weight="2"
android:orientation="vertical" >
<ScrollView android:id="#+id/scrollView1" android:layout_width="fill_parent" android:layout_height="wrap_content">
<LinearLayout android:orientation="vertical" android:paddingTop="10.0dip" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_marginBottom="2dip">
<LinearLayout
android:id="#+id/leftRow1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center" >
<ImageView
android:id="#+id/imageicon1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/icon1"
android:layout_marginRight="2dip"
android:clickable="true" />
<ImageView
android:id="#+id/imageicon2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/icon2"
android:layout_marginLeft="2dip"
android:clickable="true" />
</LinearLayout>
<LinearLayout android:id="#+id/leftRow2" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content">
<ImageView
android:id="#+id/imageicon3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/icon3"
android:layout_marginRight="2dip"
android:clickable="true" />
<ImageView
android:id="#+id/imageicon4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/icon4"
android:layout_marginLeft="2dip"
android:clickable="true" />
</LinearLayout>
</LinearLayout>
</ScrollView>
</LinearLayout>
main.java code for displaying image size dynamically
DisplayMetrics metrics = getResources().getDisplayMetrics();
iHeight = metrics.heightPixels;
iWidth = metrics.widthPixels;
leftLLWidth = (int) ((iWidth * 25) / 100);
rightLLWidth = (int) (iWidth - leftLLWidth);
leftLL = (LinearLayout) findViewById(R.id.mainlayoutLeft);
rightLL = (LinearLayout) findViewById(R.id.mainlayoutRight);
leftLL.setLayoutParams(new LinearLayout.LayoutParams(leftLLWidth, iHeight));
rightLL.setLayoutParams(new LinearLayout.LayoutParams(rightLLWidth, iHeight));
//init image buttons
img_icon1 = (ImageView) findViewById(R.id.imageicon1);
img_icon2 = (ImageView) findViewById(R.id.imageicon2);
img_icon3 = (ImageView) findViewById(R.id.imageicon3);
img_icon4 = (ImageView) findViewById(R.id.imageicon4);
btnWidth = (int) ((leftLLWidth / 2) - 3);
btnHeight = btnWidth + 60;
ViewGroup.LayoutParams button_params = img_icon1.getLayoutParams();
button_params.width = btnWidth;
button_params.height = btnHeight;
img_icon1.setLayoutParams(button_params);
//img_icon1.setOnClickListener(onMainImgClickHandler);
img_icon2.setLayoutParams(button_params);
img_icon3.setLayoutParams(button_params);
img_icon4.setLayoutParams(button_params);
Hope this explaines my issue. Thanks in Advance.
Regards
Nayeem

have you tried changing the gravity to top?
android:layout_gravity="top"

In your parent linear layout you have put width
android:layout_width="0dip"
which is not right

TextView width match drawableTop width

Is there someway to make TextView width match compound Drawable width (XML)?
For example for xml code:
<TextView
android:id="#+id/textView"
style="#style/TextIcons"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:drawableTop="#drawable/icon_contact"
android:gravity="center"
android:lines="2"
android:text="#string/contact_label" />
I get:
|---------------------|
| |-------------| |
| | | |
| | Drawable | |
| | View | |
| | | |
| |-------------| |
|[---Contact Label---]|
|---------------------|
But what i really want is:
|-----------------|
| |-------------| |
| | | |
| | Drawable | |
| | View | |
| | | |
| |-------------| |
| [---Contact---] |
| [----Label----] |
|-----------------|

You can simply get it to work by separating the image and the TextView, into a relative layout. It makes easy to specify where align some view's edges, etc.
The following code should do something close to what you want:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/icon_contact"
android:id="#+id/imageView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="10dp">
</ImageView>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="#string/contact_label"
android:id="#+id/textView"
android:layout_below="#+id/imageView"
android:layout_alignRight="#+id/imageView"
android:layout_alignLeft="#+id/imageView"/>
</RelativeLayout>

How can I fix this RelativeLayout?

I'd like to see the following layout work:
--------------------------
| ----------- |
| |TextView1| |
| ----------- |
| ---------------------- |
| |EditText1 | |
| ---------------------- |
| ----------- |
| |TextView2| |
| ----------- |
| ---------------------- |
| |EditText2 | |
| ---------------------- |
| ----------- |
| |TextView3| |
| ----------- |
| ---------------------- |
| | | |
| | | |
| | | |
| | ImageView | |
| | | |
| | | |
| | | |
| |--------------------| |
| --------- -------- |
| |Button1||Button2| |
| --------- -------- |
| ---------------------| |
| | ButtonBar | |
| ---------------------- |
|------------------------|
My issue: I can't make Button1 and Button2 work in this layout. They either go below the ImageView, hidden behind the ButtonBar or they get shrunk to nothing between the bottom of the ImageView and the top of the ButtonBar.
The current XML-code:
<?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="fill_parent"
android:orientation="vertical" >
<RelativeLayout
android:id="#+id/relativeLayout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/footer" >
<TextView
android:id="#+id/textPostUser"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="user" />
<EditText
android:id="#+id/editPostUser"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="#id/textPostUser"
android:hint="user"
android:maxLength="40" >
<requestFocus />
</EditText>
<TextView
android:id="#+id/textPostComment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/editPostUser"
android:text="comment" />
<EditText
android:id="#+id/editPostComment"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="#id/textPostComment"
android:hint="comment"
android:maxLength="200"
android:maxLines="3" >
</EditText>
<TextView
android:id="#+id/textPostCharacterCount"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/editPostComment"
android:text="characters"
android:textSize="5pt" />
<ImageView
android:id="#+id/imagePostResult"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="#id/textPostCharacterCount"
android:src="#drawable/camera_icon" />
<Button
android:id="#+id/buttonPostRotateLeft"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_below="#id/imagePostResult"
android:text="left" />
<Button
android:id="#+id/buttonPostRotateRight"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_below="#id/imagePostResult"
android:layout_toRightOf="#id/buttonPostRotateLeft"
android:text="right" />
</RelativeLayout>
<LinearLayout
android:id="#+id/footer"
style="#android:style/ButtonBar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:orientation="horizontal" >
<Button
android:id="#+id/buttonPostSave"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="save" />
</LinearLayout>
</RelativeLayout>
How do I make the left/right buttons appear below the imageview and above the buttonbar?
I'd like to at least keep the fill_parent in both height/width of the ImageView as it scales pretty nicely on different resolutions.

Your ImageView is set to fill_parent so there is no space left for the buttons below. You can switch the buttons and the imageview so the imageview takes all the space left when the buttons are already included:
<Button
android:id="#+id/buttonPostRotateLeft"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:text="left" />
<Button
android:id="#+id/buttonPostRotateRight"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_toRightOf="#id/buttonPostRotateLeft"
android:text="right" />
<ImageView
android:id="#+id/imagePostResult"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_above="#id/buttonPostRotateLeft"
android:layout_below="#id/textPostCharacterCount"
android:src="#drawable/camera_icon" />

Why not putting the two buttons inside a horizontal LinearLayout?

Your buttons are set to android:layout_alignParentBottom="true", as well as the linear layout. The latter will hide the former since it comes last in the xml code.
Try putting your buttons in a linear layout and align it above the footer android:layout_above="#+id/footer"