Alternative to LinearLayouts' layout_weight attribute? - android

I need a View to hold a number of TextViews, and the exact number I will not know unfortunately. I need the TextViews to sort of stack either under each other or right next to each other (imagine Tetris, but with just rectangles or squares). The way I have tried thinking about it is using LinearLayout to hold them either horizontally or vertically. I then use their weights to stretch them appropriately if they are next to each other. Otherwise, I use a vertical orientation. Problem is the performance with nested LinearLayouts with more complicated stacks. I thought about using RelativeLayout, but that wouldn't work because I need the TextViews to not overlap. So like if they are next to each other, they need to each take enough space evenly. With layout_weight it works great. I was hoping someone had any idea on how to make this work right/alternative.
Heres an example that is giving me a warning (only a simple example of what I am doing programmatically):
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_weight="1">
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Hello World 1"
android:background="#000000"
android:layout_weight="1"/>
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Hello World 3"
android:background="#000000"
android:layout_weight="1"/>
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Hello World 4"
android:background="#000000"
android:layout_weight="1"/>
</LinearLayout>
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_weight="1">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Hello World 2"
android:background="#000000" />
</LinearLayout>
I've tried it with RelativeLayout by the way, but one of the TextView's needs to be a set size, but I need them to take space evenly. I won't know specific sizes. Measuring the screen width and dividing it that way is also both clunky and not precise. I appreciate anybodies input.
Edit: So I've been thinking about it some more and thought of a solution using RelativeLayout. There is a nice example in the Android docs, but the only problem is one of the Views needs to be a set size so the other one could stretch. But if there is a way to allow all of them not to have a set size, that could work too, so then they can stretch. Anyone tried doing that at some point?

It's a bit unclear what your final use case looks like, so I don't know if this will completely solve your problem, but you might take a look at TableLayout (docs link). It's based on LinearLayout so items can still be defined to evenly occupy a given space, but it allows you to define your positions and spans in terms of rows and columns.
So, for instance, your example code would look like:
<TableLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:stretchColumns="*" >
<!-- Wrap all items in a given row in a TableRow -->
<TableRow>
<TextView
android:text="Hello World 1"
android:background="#000000"/>
<TextView
android:text="Hello World 3"
android:background="#000000"/>
<TextView
android:text="Hello World 4"
android:background="#000000"/>
</TableRow>
<!-- If a child occupies an entire row, it can be by itself -->
<TextView
android:text="Hello World 2"
android:background="#000000"/>
</TableLayout>
You can also use the android:layout_column and android:layout_span attributes to define exactly which column an item should be in, and how many columns it should occupy. Also note that TableLayout and TableRow have basically ignore any layout params applied and use very specific (documented) parameters, so adding them to your code will only confuse what is actually going on. Of course, this can all be built programmatically as well as in XML.
If this does not provide the flexibility you need, I would then recommend creating your own custom layout that either extends or is based on LinearLayout. The mechanism is uses to measure children with weight is not that complex, and then you can override how each child is placed after measurement. Here is a source link to LinearLayout if you want to see how the platform does these things.

Update: As we know the percent support library is deprecated from API level 26. ConstraintLayout is the new way to achieve the same flat xml structure.
Updated Github Project
Updated Samples:
<android.support.constraint.ConstraintLayout
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/fifty_thirty"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="#ffff8800"
android:gravity="center"
android:text="#string/fifty_fifty_text"
android:textColor="#android:color/white"
app:layout_constraintHeight_default="percent"
app:layout_constraintHeight_percent="0.5"
android:textSize="25sp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintWidth_default="percent"
app:layout_constraintWidth_percent="0.5" />
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
android:background="#ffff5566"
android:gravity="center"
android:text="#string/fifty_fifty_text"
android:textColor="#android:color/white"
android:textSize="25sp"
app:layout_constraintHeight_default="percent"
app:layout_constraintHeight_percent="0.5"
app:layout_constraintLeft_toRightOf="#id/fifty_thirty"
app:layout_constraintTop_toBottomOf="#id/fifty_thirty"
app:layout_constraintWidth_default="percent"
app:layout_constraintWidth_percent="0.5" />
</android.support.constraint.ConstraintLayout>
Deprecated
update: We can use android support library for the same.
compile 'com.android.support:percent:23.0.0'
Consider this demo for dividing the screen into 50-50 percent.
<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/fifty_huntv"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="#ff7acfff"
android:text="20% - 50%"
android:textColor="#android:color/white"
app:layout_heightPercent="20%"
app:layout_widthPercent="50%" />
<TextView
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_toRightOf="#id/fifty_huntv"
android:background="#ffff5566"
android:text="80%-50%"
app:layout_heightPercent="80%"
app:layout_widthPercent="50%"
/>
</android.support.percent.PercentRelativeLayout>
Output:
Demo HERE!!!
GitHub Project HERE!!!

Related

Is there a better way to align the text in different buttons in Android?

It is my firs time that I try to design a good UI instead of debugging apps, so I am new to this type of stuff.
I have three buttons under each other and the text should be aligned correctly. So that the "F" of Favorites starts at the same horizontal point as the "E" of Equalizer.
The way I did it, is not satisfying. I worked with paddingEnd and just tried out until it looked almost equal on the horizontal axis.
One other idea was to make the gravity center_vertical|left and instead use drawablePadding. This did not work because the width of the buttons is defined as match_parent. But also when I change the buttons to android:layout_width="wrap_content" and remove android:paddingStart and android:paddingEnd for testing, it does not work.
I got these info out of android:drawableLeft margin and/or padding
There should be a way to make it "easy" to fulfill the design I require. Has someone an idea what I am making wrong and has a solution for me?
The code of the xml layout file and a screenshot of the result are attached.
If something else is required to solve this question, then just ask me straight away.
Screenshot of the buttons
<androidx.constraintlayout.widget.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"
tools:context=".MainActivity">
<LinearLayout
android:id="#+id/menu"
android:layout_width="300dp"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#drawable/border"
android:paddingEnd="0.3dip"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<Button
android:id="#+id/favButton"
android:layout_width="match_parent"
android:layout_height="80dp"
android:insetTop="1dp"
android:insetBottom="1dp"
android:paddingStart="50dp"
android:paddingEnd="15dp"
android:background="#drawable/rectangle"
android:drawableLeft="#drawable/ic_bxs_heart"
android:text="#string/favorites"
android:textColor="#000000"
android:textSize="16sp"/>
<Button
android:id="#+id/eqzButton"
android:layout_width="match_parent"
android:layout_height="80dp"
android:insetTop="1dp"
android:insetBottom="1dp"
android:paddingStart="50dp"
android:background="#drawable/rectangle"
android:drawableLeft="#drawable/ic_equalizer"
android:text="#string/equalizer"
android:textColor="#000000"
android:textSize="16sp"/>
<Button
android:id="#+id/settingsButton"
android:layout_width="match_parent"
android:layout_height="80dp"
android:insetTop="1dp"
android:insetBottom="1dp"
android:paddingStart="50dp"
android:paddingEnd="27dp"
android:background="#drawable/rectangle"
android:drawableLeft="#drawable/ic_settings"
android:text="#string/settings"
android:textColor="#000000"
android:textSize="16sp"/>
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

Can the Android Flow virtual layout handle variable-width Views

Android recently introduced Flow virtual layout but all of the examples I've seen show child Views that have the same width so it ends up laying out in a grid, instead of a jagged flow.
I've seen variable width handles for flexbox-layout and Dhaval Solanki's FlowLayout.
One other person asked a similar question (Which android layout to use for distributing variable width buttons to fill a screen?), but they were asking generally how to do it, whereas I'm asking specifically how to do it with Flow.
Can Flow handle variable-width Views? How?
Here is a simple example of how it can be achieved (ConstraintLayout:2.0.0-beta2):
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
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">
<androidx.constraintlayout.helper.widget.Flow
android:layout_width="0dp"
android:layout_height="wrap_content"
app:constraint_referenced_ids="text1,text2,text3,text4,text5"
app:flow_wrapMode="chain"
app:flow_horizontalStyle="packed"
app:flow_horizontalBias="0"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"/>
<TextView
android:id="#+id/text1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
android:background="#FF0000"/>
<TextView
android:id="#+id/text2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="That is a very long textview that is very, very long"
android:background="#00FF00"/>
<TextView
android:id="#+id/text3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="text3 which is somewhat long"
android:background="#0099FF"/>
<TextView
android:id="#+id/text4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="text4"
android:background="#999999"/>
<TextView
android:id="#+id/text5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="text5"
android:background="#9900FF"/>
</androidx.constraintlayout.widget.ConstraintLayout>
Result:
app:flow_wrapMode="chain" allows for the chain to wrap to the next line when there's not enough space
app:flow_horizontalStyle="packed" is necessary to be able to set the bias
app:flow_horizontalBias="0" aligns the Views to the left
app:flow_horizontalGap="Xdp" can be used to set a gap between the Views
Other wrap styles (spread and spread_inside) will not take the bias into account as they have a predefined way of laying out the Views

Android make one element take rest of space

I have an activity that has one element that is rooted to the top, and another element that should take the rest of the space available. The first element's content will change over time and require different amounts of space, and the second element needs to change size with it. This is a simplified version of what I have already:
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<TextView
android:id="#+id/textview_A"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
/>
<TextView
android:id="#+id/textview_B"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#+id/textview_A"
app:layout_constraintBottom_toBottomOf="parent"
/>
</android.support.constraint.ConstraintLayout>
The way it is currently, the top element is correct, but the second element isn't. It will adjust its position to be halfway the bottom of the top element and the bottom of the parent element, but its height is the same as its content, not all available space. How can I achieve this?
Set layout weight = 1
android: layout="1"
Alternatively, try linearlayout like this:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="text" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#mipmap/ic_launcher" />
<Button
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="D" />
</LinearLayout>
notice this special snippet:
android:layout_width="0dp"
android:layout_weight="1"
Please search before posting a question like this.
Some of the previous answers on this
Set width to match constraints in ConstraintLayout
Restrict width in ConstraintLayout by another view
Change android:layout_height of #id/testview_B to 0dp. Something like
<TextView
android:id="#+id/textview_B"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintTop_toBottomOf="#id/textview_A"
app:layout_constraintBottom_toBottomOf="parent"
/>

Gravity of two side-by-side TextViews

I'm trying to have two TextViews side-by-side, and I want one to be touching the right-side of the screen and the other, the left-side. I don't want to define the widths using numbers because screens of different sizes would behave differently. So I'm trying to use layout_gravity, which is not working for some reason.
<LinearLayout
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:textSize="16dp"
android:layout_gravity="left"
android:text="rrr"
android:textColor="#color/secondTextColor"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:textSize="16dp"
android:text="sss"
android:textColor="#color/secondTextColor" />
</LinearLayout>
Can anyone tell me why? Thanks!
You can create one LinearLayout for each TextView as follows :
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="start">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="16dp"
android:text="rrr"
android:textColor="#f2f2"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="end">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="16dp"
android:text="sss"
android:textColor="#f3f3" />
</LinearLayout>
</LinearLayout>
And the important thing is that in your first LinearLayout you put android:gravity="start" and in your second one android:gravity="end", then it will work :)
Use end instead of right to ensure correct behavior in right-to-left locales.
Why is "end" better than "right"?
Using Gravity#LEFT and Gravity#RIGHT can lead to problems when a layout is rendered in locales where text flows from right to left.
Use Gravity#START and Gravity#END instead. Similarly, in XML gravity and layout_gravity attributes, use start rather than left.
For XML attributes such as paddingLeft and layout_marginLeft, use paddingStart and layout_marginStart.
NOTE: If your minSdkVersion is less than 17, you should add both the older left/right attributes as well as the new start/right attributes. On older platforms, where RTL is not supported and the start/right attributes are unknown and therefore ignored, you need the older left/right attributes. There is a separate lint check which catches that type of error.
(Note: For Gravity#LEFT and Gravity#START, you can use these constants even when targeting older platforms, because the start bitmask is a superset of the left bitmask. Therefore, you can use gravity="start" rather than gravity="left|start".)
You can try with android:layout_weight & android:gravity .
Read What does android:layout_weight mean & Layout Weight
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:weightSum="1" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.5"
android:gravity="left"
android:text="Intellij" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0.5"
android:gravity="right" // You can add end instead of right
android:text="Amiya" />
</LinearLayout>
You could use android:layout_weight="1" on TextView's and 0dp for width.

how to align an element to right in horizontal LinearLayout?

I have a LinearLayout that contains a lot of TextViews and ImageButtons, I want to align some of these elements to right, i had a look at this and this but i can't use their tips as i can't change the orientation and can't make android.gravity:right as i don't want to align all the elements to right, also i can't use nested layouts or but the desired elements into RelativeLayout because that shifts the rest of elements to the left and i want them at the center.
this is my code:
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="0.15"
android:layout_marginTop="10dp"
android:layout_gravity="center"
android:gravity="center"
android:background="#drawable/media_mediabar"
android:orientation="horizontal" >
<ImageButton
android:id="#+id/move_backward"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:adjustViewBounds="true"
android:background="#android:color/transparent"
android:clickable="true"
android:scaleType="centerInside"
android:src="#drawable/media_button_rewind"
android:layout_marginLeft="7dp"
android:layout_marginRight="7dp"
android:tag="released"/>
<ImageButton
android:id="#+id/rmeote_mines"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:adjustViewBounds="true"
android:background="#android:color/transparent"
android:clickable="true"
android:scaleType="centerInside"
android:src="#drawable/remote_minus" />
<TextView
android:id="#+id/remote_plus_minus"
android:text="0"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#android:color/white"
android:layout_gravity="center"
android:layout_marginTop="15dp"
android:layout_marginBottom="15dp" />
.
.
.<!.. some other elements ..!>
</LinearLayout>
The desired result:
The simplest solution would be using empty views with weights as separators.
<LinearLayout android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<!-- Left button -->
<Button ...
... />
<View android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />
<!-- Middle button -->
<Button ...
... />
<View android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />
<!-- Right button -->
<Button ...
... />
</LinearLayout>
The separator views can be made invisible as an optimization, because they don't draw anything and are used only for layout. You can tweak the actual 'layout_weight' values to get the desired layout. Starting from API level 14 you can use instances of Space as separators which will improve performance and readability (there is also a version of Space in the support library).
For such a complex layout you'd be way better of using RelativeLayout instead.
i can't use nested layouts
Then you can't solve your problem.
Nested layout are the heart of Android layout, to create such complex view that you desire, I think you must use nested layouts.
#Ridcully suggested you to use RelativeLayout, this is a good idea. You can combine it with few linear layouts and you be fine.
I think that RelativeLayout should be your base layout.

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