Develop Reference

Different size of ImageView on different devices

I have a little problem with ImageView on differents screens with different dpi like this:
On second screen there are original dimensions of imageviews. But on first screen images are bigger and moved out. How i can set proportional dimensions and margins to ImageView.
Here is my code:
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="#+id/textLayoutIntro">
<ImageView
android:id="#+id/first_slide_second_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:src="#mipmap/first_slide_second_image"
android:layout_alignParentStart="true"
android:layout_alignStart="#+id/firstSlideTelephone"
android:layout_marginTop="100dp"
android:layout_marginStart="20dp"/>
<ImageView
android:id="#+id/first_slide_third_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#mipmap/first_slide_third_image"
android:scaleType="fitCenter"
android:adjustViewBounds="true"
android:layout_alignParentEnd="true"
android:layout_alignEnd="#+id/firstSlideTelephone"
android:layout_marginEnd="30dp"
android:layout_marginTop="100dp"/>
<ImageView
android:id="#+id/firstSlideTelephone"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#mipmap/first_slide_telephone"
android:layout_centerInParent="true"
android:adjustViewBounds="true"
android:scaleType="centerInside"/>
<ImageView
android:id="#+id/first_slide_first_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:src="#mipmap/first_slide_first_image"
android:layout_marginStart="-30dp"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true"
android:maxWidth="138dp"
android:maxHeight="138dp"/>
<ImageView
android:id="#+id/first_slide_fourth_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:src="#mipmap/first_slide_fourth_image"
android:layout_alignParentBottom="true"
android:layout_marginBottom="100dp"/>
</RelativeLayout>
Thanks in advance)

Instead of RelativeLayout, use constraintlayout with vertical and horizontal guidelines. That way, the content sizes up or down to whatever device screen size. Like the sample below.
<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:id="#+id/parent"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorAccent"
android:clickable="true"
tools:context="com.example.example.Fragments.ExampleFragment">
<android.support.constraint.Guideline
android:id="#+id/fragment_guideline_v_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.1" />
<android.support.constraint.Guideline
android:id="#+id/fragment_guideline_v_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.9" />
<android.support.constraint.Guideline
android:id="#+id/fragment_guideline_h_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.1" />
<android.support.constraint.Guideline
android:id="#+id/fragment_guideline_h_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.9" />
<ImageView
android:id="#+id/imageview"
android:layout_width="0dp"
android:layout_height="0dp"
android:contentDescription="#string/none"
app:layout_constraintStart_toEndOf="#+id/fragment_guideline_h_1"
app:layout_constraintEnd_toStartOf="#+id/fragment_guideline_h_2"
app:layout_constraintTop_toBottomOf="#+id/fragment_guideline_v_1"
app:layout_constraintBottom_toTopOf="#+id/fragment_guideline_v_2"
app:srcCompat="#drawable/forgot_password_arrow_back" />
</android.support.constraint.ConstraintLayout>

I've had same problem but I've found this: https://github.com/intuit/sdp
It's a library with dimensions represented by sdp. It just library with dp but scaled for different screen sizes.

You can use percentage for ImageView width and height. For example, use ConstraintLayout and for ImageView:
<ImageView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_constraintWidth_percent="0.7" />

It's possible to solve many ways. The above bros already said possible to solve by Constraint layout.
It's also possible to solve by Linear layout. Just use weight_sum. Add 2 View add the top and bottom and at the middle add your image. Weight perfectly work dynamically (may you know).
But if I was in this situation, I would be solved it using sdp & ssp library. The library most of the time works perfectly.
only for font/text size: ssp. &
For any others except font: sdp

How to position ImageView without taking the entire screen?

I am trying to code one of my first android apps. I am trying to position a text below an image, but the image takes up most of the screen and one of the textviews which are supposed to be below it are not displayed. I am using a RelativeLayout.
Here is my code snippet.
<RelativeLayout
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.jsk.myapp.MainActivity">
<TextView
android:id="#+id/t1"
android:layout_width="wrap_content"
android:text="My App"
android:layout_centerHorizontal="true"
android:textSize="30sp"
android:layout_alignParentTop="true"
android:layout_height="wrap_content" />
<ImageView
android:scaleType="centerCrop"
android:id="#+id/img"
android:layout_below="#id/t1"
android:layout_width="match_parent"
android:layout_height="200dp"
android:src="#drawable/i1"
/>
<TextView
android:id="#+id/t2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/img"
android:textSize="24sp"
android:text="Description"/>
</RelativeLayout>
I have also tried changing the scale type of the imageview, but it doesn't work. Only when I explicitly specify the width and height parameters of the image, the text is visible below the image.
What changes can I make in this code to get the desired output ?

If you add a rough diagram of what you want to achieve your question can be answered better. From my understanding, and by looking at your code it seems you are trying to add 2 TextView's at the top and bottom (one each) and then an ImageViewsandwiched in between.
First, add the 2 TextView's. Set the one as android:layout_alignParentTop = true and android:layout_alignParentBottom = true. Then add the ImageView. In the ImageView, you can set android:layout_height = "wrap_content" and then android:layout_below=<id of the top text view> as well as android:layout_above = <id of the bottom text view>.
So something like this:
<RelativeLayout
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.jsk.myapp.MainActivity">
<TextView
android:id="#+id/t1"
android:layout_width="wrap_content"
android:text="My App"
android:layout_centerHorizontal="true"
android:textSize="30sp"
android:layout_alignParentTop="true"
android:layout_height="wrap_content" />
<TextView
android:id="#+id/t2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:textSize="24sp"
android:text="Description"/>`
<ImageView
android:scaleType="centerCrop"
android:id="#+id/img"
android:layout_below="#id/t1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:src="#drawable/i1"
android:layout_above="#id/t2"
/>
</RelativeLayout>

If you're using wrap_content for your ImageView's height and if your ImageView's actual image is large enough then it will surely take up entire space.
In that case, you'll have to explicitly mention exact height of the View, so that text below is show up.
What you want to do to fix this situation is to change actual height of the image itself. If you do that, image will fit itself entirely but takes less height and then text should show up.
So you have two options,
1) Either fix your image height in your layout, OR
2) Fix actual image height so that it's more appropriate in your usecase
I hope this answers your question.

You need to assign a size for ImageView based on screen size
Use PercentRelativeLayout
My compileSdkVersion is 24 so I use compile 'com.android.support:percent:24.0.0' inside my app:gradle dependencies
example :
<android.support.percent.PercentRelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/t1"
android:layout_width="wrap_content"
android:text="My App"
android:layout_centerHorizontal="true"
android:textSize="30sp"
android:layout_alignParentTop="true"
android:layout_height="wrap_content" />
<ImageView
android:scaleType="centerCrop"
android:id="#+id/img"
android:layout_below="#id/t1"
android:layout_width="match_parent"
app:layout_heightPercent="50%" <---------- here its taking 50% of screen height
android:src="#drawable/myImageName"
/>
<TextView
android:id="#+id/t2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/img"
android:textSize="24sp"
android:text="Description"/>
</android.support.percent.PercentRelativeLayout>
If you use LinearLayout go for layout_weight attribute

make t2 alignParentBottom true
and
let img view layout_above t2
<RelativeLayout
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.jsk.myapp.MainActivity">
<TextView
android:id="#+id/t1"
android:layout_width="wrap_content"
android:text="My App"
android:layout_centerHorizontal="true"
android:textSize="30sp"
android:layout_alignParentTop="true"
android:layout_height="wrap_content" />
<ImageView
android:scaleType="centerCrop"
android:id="#+id/img"
android:layout_below="#id/t1"
android:layout_above="#+id/t2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="#drawable/i1"
/>
<TextView
android:id="#id/t2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:textSize="24sp"
android:text="Description"/>
</RelativeLayout>

Flexible Horizontal Layout with `layout_weight` and `maxWidth`

I have a TextView and a square ImageView that I would like to show in a horizontal linear layout. Each should take half of the parent view's width and the height should fit the content (i.e. the image). The text should be centered vertically.
Additional constraint is that the image should not grow beyond a given maxWidth (= maxHeight), and excess width should be made available to the TextView. Obviously, this conflicts with the 50/50 rule above. Is there a way to prioritize the constraints, i.e. allow the image to take half of the space unless it exceeds a given size?
These are layouts I tried:
The first one nicely stretches the left side to the available space. But the image takes more than half of the width as its layout_weight is not specified (as in image below).
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:orientation="vertical"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center_vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Some text."/>
</LinearLayout>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxWidth="200dp"
android:adjustViewBounds="true"
android:src="#drawable/image" />
</LinearLayout>
When I add layout_weight to the ImageView it always takes half of the width and ignore the maxWidth (see image below).
<ImageView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:maxWidth="200dp"
android:adjustViewBounds="true"
android:src="#drawable/image" />
Enclosing the ImageView in another LinearLayout enables the maxWidth again, but the enclosing LinearLayout still takes half of the available space (see image below).
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="right">
<ImageView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:maxWidth="200dp"
android:adjustViewBounds="true"
android:src="#drawable/image" />
</LinearLayout>
Another option I have found for similar scenarios is to use a RelativeLayout with an invisible view as a center divider, but that locks the division to 50/50 (or wherever the divider is placed).

Okay, gonna go on ahead and post the xml I created, it's pretty much simple, it does most of your conditions.. One thing I'm having trouble with is the part where each view takes half of the parent view's width. Hope this still helps you in some way.
sample_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="2dp"
android:background="#android:color/darker_gray">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/img_sample"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginRight="2dp"
android:layout_toLeftOf="#id/img_sample"
android:background="#color/colorPrimary"
android:gravity="center_vertical"
android:text="Some text." />
<ImageView
android:id="#id/img_sample"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_marginLeft="2dp"
android:adjustViewBounds="true"
android:maxWidth="200dp"
android:src="#drawable/sample_img" />
</RelativeLayout>
Here is a sample screenshot:
If ever you figure out how to the the half of each thing, kindly comment it here, It'd be nice to know about it for possible future use. :)
PS: Have you considered doing the half of each thing programatically? Like checking the LayoutParams then dynamically setting weightSum and the layout_weights.
Sample Image retrieved from this link

<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ImageView
android:id="#id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentTop="true"
android:layout_weight="1"
android:adjustViewBounds="true"
android:background="#color/blue"
android:src="#drawable/ic_launcher" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_centerVertical="true"
android:layout_margin="5dp"
android:layout_toStartOf="#id/imageView"
android:background="#color/colorPrimary"
android:padding="10dp"
android:text="Some text. " />
</RelativeLayout>

It won't be a perfect solution in term of performance. But you can achieve it by playing with FrameLayout and ImageView.
Here is the output:
Layout.xml:
<?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="match_parent"
android:background="#color/textGray"
android:orientation="vertical">
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#color/skyBlue">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="#android:color/white">
<ImageView
android:id="#+id/imageView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxWidth="200dp"
android:src="#drawable/ic_settings"
android:visibility="invisible" />
<TextView
android:id="#+id/TextView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:text="!" />
</FrameLayout>
<ImageView
android:id="#+id/imageView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:maxWidth="200dp"
android:src="#drawable/ic_settings" />
</LinearLayout>
</FrameLayout>
</LinearLayout>
In order to achieve desire behaviour, You would have to set same images to both imagesviews in this layout. one of them is invisble, It is just helping to make parent with same width and heights which would lead us to create TextView with same dimensions.
Note: If you want to change textView alignment, you can do it with layout_gravity or gravity.

Change the Image Size without changing its Place Holder

I have some ImageView in a Horizontal LinearLayout. I set their size in percentage mode.
<LinearLayout
android:weightSum="1"
android:orientation="horizontal" >
<ImageButton
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="0.25"
android:scaleType="fitStart"
android:src="#drawable/pjc_news_icon" />
</LinearLayout>
now if I install my software in a small size device, the width of images will get smaller to fit specified percent of their parent layout. their height will get smaller too. but their place holder's height doesn't change. I mean they have an useless blank space in their bottom.

try adding another view so that it covers up the remaining space.
<LinearLayout
android:weightSum="1"
android:orientation="horizontal" >
<ImageButton
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="0.25"
android:scaleType="fitStart"
android:src="#drawable/pjc_news_icon" />
<View
android:layout_width="0dp"
android:layout_height="1dp"
android:layout_weight="0.75"
/>
</LinearLayout>
Just give a try to this, hop it works for you.

I found the answer by myself.
I added the "adjustViewBounds" property to my ImageView and set it's value true. then the space below the ImageView removed.
<LinearLayout
android:weightSum="1"
android:orientation="horizontal" >
<ImageButton
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="0.25"
android:scaleType="fitStart"
android:src="#drawable/pjc_news_icon" />
</LinearLayout>

Button taking too much space

I still dont really get it how many space layouts take.
I have the following xml.
The inner LinearLayout's for the bottom space height is set to wrap_content, so it should take the height of the maximum height in there. Which is 52dp. And there is the ImageButton which is set to wrap_content, so the button should be centered vertically on the right side, since its an 24dp image (in xhdpi it has 32x32 pixels). So why is it stretched over the full height like displayed here?:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="2dp">
<de.ph1b.audiobook.utils.SquareImageView
android:id="#+id/cover"
android:scaleType="fitXY"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/white"
android:layout_gravity="bottom">
<TextView
android:id="#+id/title"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="52dp"
android:paddingLeft="16dp"
android:maxLines="2"
android:ellipsize="end"
android:paddingRight="16dp"
android:gravity="center_vertical"
android:textSize="16sp" />
<ImageButton
android:id="#+id/editBook"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
style="?android:attr/borderlessButtonStyle"
android:layout_gravity="center_vertical"
android:src="#drawable/ic_more_vert_grey600_24dp" />
</LinearLayout>
</LinearLayout>

either #drawable/ic_more_vert_grey600_24dp is larger than you think or borderlessButtonStyle has a larger background.
Please check the size. I have replicated the behavior and the ImageButton is set to wrap_content and is centered.

change your image button code
<ImageButton
android:id="#+id/editBook"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
style="?android:attr/borderlessButtonStyle"
android:scaleType="fitXY"
android:gravity="center_vertical"
android:src="#drawable/ic_more_vert_grey600_24dp" />