I have a relative layout with a margin and a floating action button that is nested inside this layout.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
android:layout_margin="#dimen/activityMargin"
android:orientation="vertical"
android:clipToPadding="false">
<android.support.design.widget.FloatingActionButton
android:id="#+id/id_FABSave"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
app:srcCompat="#drawable/ic_save_white"/>
</RelativeLayout>
As you can see in the attached picture, the drop shadow of the floating action button is cut off. How does this happen and how can it be fixed?
In your relative layout tag, use padding instead of margin and add the attribute android:clipToPadding="false" to avoid the shadows being cut.
<RelativeLayout 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"
android:padding="#dimen/activityMargin"
android:clipToPadding="false">
Problem is that shadows are cut by bounds of view or view group. To tackle this issue you have to use:
android:clipChildren
Defines whether a child is limited to draw inside of its bounds or not.
android:clipToPadding
Defines whether the ViewGroup will clip its children and resize (but not clip) any EdgeEffect to its padding, if padding is not zero.
Problem is that you have to set this to many views in xml if you want to render shadow. I resolved this issue on level of themes.xml. In my top level theme I just set:
<item name="android:clipChildren">false</item>
<item name="android:clipToPadding">false</item>
Then, if there is space on screen, shadow is rendered. I hope it won't break something else.
EDIT: It breaks some views. For example CameraPreview will set black background to whole screen. Be careful with scrolling views, etc.
Related
[![my image][1]][1]
As. you can see from the image i have a rounded corner shape ..but i want to have a shadow just on the top (there is no where else for it anyway since its covered on the other ends). How can i place a shadow just at the top of this cardView ? here is what i have so far and i've tried using two framelayouts earlier.
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/viewRoot"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<com.google.android.material.card.MaterialCardView
android:theme="#style/Theme.MaterialComponents.Light"
android:id="#+id/greenCardView"
android:layout_width="match_parent"
android:layout_height="100dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:cardCornerRadius="16dp"
app:cardElevation="0dp"
android:clipToOutline="true"
android:clipToPadding="true"
android:clipChildren="true"
app:cardPreventCornerOverlap="true"
app:cardBackgroundColor="#color/green">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/contentContainer"
android:layout_width="match_parent"
android:background="#color/transparent"
android:layout_height="54dp"/>
</androidx.constraintlayout.widget.ConstraintLayout>
i also need the shadow to have no background under it ..so it should not be on a white background, i just want the shadow on top alone on a transparent background.
update: after i udated to 70dp elevation the shadow is only appearing on the bottom :
[![enter image description here][2]][2]
notice the shadow is only appearing at the bottom . how can i make shadow just at the top
[1]: https://i.stack.imgur.com/8XC6l.png
[2]: https://i.stack.imgur.com/egRoB.png
Increse the value of
app:cardElevation="0dp"
it was how i was attaching the scrollview to the cardview ..i used a space view to attach it a bit lower and it works great now (since i dont have access to negative margins) ..thanks
what i learned is that when you have a scrollview attached to a cardview then you should attach the scrollview a few pixels away from the top so that it does not look cut off when it scrolls.
I stumbled upon something weird. I am using the same CardView component in more than one place in my app, all with the same elevation (3dp), and they all looks the same. However, for one scenario I need to embed the CardView inside a ScrollView. I didn't change anything in the CardView configuration, but the shadow now looks different.
This is my layout:
<ScrollView 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"
android:clipChildren="false"
android:clipToPadding="false"
android:padding="16dp"
android:scrollbars="none">
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clipChildren="false"
android:clipToPadding="false"
app:cardCornerRadius="8dp"
app:cardElevation="3dp"
app:cardUseCompatPadding="true">
<!-- some other views-->
</androidx.cardview.widget.CardView>
</ScrollView>
In the picture below you can see on the right the CardView and on the left the two shadows: on the top the shadow generated by the CardView alone, on the bottom the one generated when the CardView is inside a ScrollView. As you can see the second one appears darker and thicker.
NOTE: The background color (#FAFAFA) is the same in both scenario.
For both cases, I would check the following properties as it could contribute to the difference you're seeing:
getTranslationZ()
getElevation()
getOutlineAmbientShadowColor() (this is only valid in API 28+)
getOutlineSpotShadowColor() (this is only valid in API 28+)
Plus, checking Layout inspector to see if there's any view that could affect to the rendering.
Also, this article from Sebastiano Poggi could be of help.
I have a CardView within a ConstraintLayout.
This view is then inflated and added to a LinearLayout.
I would like the CardView to cast a shadow on the next CardView, but it seems to be clipped by the ConstraintLayout. How can I get the elevation shadow to show on the CardView without providing more padding or margins for it?
i.e. How can I cast the shadow on an adjacent item?
<LinearLayout>
<ConstraintLayout>
<CardView> <-- This view's shadow is cut
...
</CardView>
</ConstraintLayout>
<ConstraintLayout>
<CardView>
...
</CardView>
</ConstraintLayout>
<LinearLayout>
Try adding this comment inside your card view that's enough
card_view:cardUseCompatPadding="true"
How can I get the elevation shadow to show on the CardView without providing more padding or margins for it?
i.e. How can I cast the shadow on an adjacent item?
You can't, for both a practical reason and a conceptual one.
The practical reason comes down to how the Android framework draws CardView shadows. On older API levels, the card is inset within its own bounds and that extra space is used to draw the shadow. So even if you had two cards immediately next to each other, they'd still have "space" between them due to these insets. From the documentation:
Before Lollipop, CardView adds padding to its content and draws shadows to that area.
On Lollipop and higher, shadows are drawn within the parent's bounds, not within the CardView's bounds. Still, the parent will clip the shadow if there isn't enough space between the card's edges and the parent's edges to draw the whole shadow. In your example, each CardView is in a separate parent, so even if you put those parents immediately next to each other, each parent would still clip its card's shadow.
As for the conceptual reason, that's just not how shadows work (in nature). If you have two cards at the same elevation, even if they're right next to each other, the top card wouldn't cast a shadow on the bottom card.
Try to add
app:cardElevation="10dp"
In order to use app:cardElevation you have to add to your LinearLayout:
xmlns:app="http://schemas.android.com/apk/res-auto"
I tried this in a test project and the elevation should work this way. Below is my code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
tools:context="ro.helpproject.funcode.help.MainActivity">
<android.support.constraint.ConstraintLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="50dp"
app:cardElevation="10dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TEST TEST" />
</android.support.v7.widget.CardView>
</android.support.constraint.ConstraintLayout>
<android.support.constraint.ConstraintLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="50dp"
app:cardElevation="10dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TEST TEST" />
</android.support.v7.widget.CardView>
</android.support.constraint.ConstraintLayout>
</LinearLayout>
CardView needs padding around it for shadow to appear.
If app:cardUseCompatPadding="true" adds the shadow for you but you don't want the extra padding from 4 directions (LRTB), you need to add margin to the CardView yourself.
Enable Developer options -> Show layout boundaries and if you see that there is no empty space around your CardView. Then that's probably the reason shadow not appearing.
I'm building a splash screen with a dimmed background. Im using RelativeLayout as the base for all the widgets. In order to create and dim effect I created a dim.xml, which is essentially a black shape (to set the opacity later).
<?xml version="1.0" encoding="utf-8"?>
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid android:color="#000000" />
The layout:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:background="#drawable/background"
android:id="#+id/ActivityLayout">
<ImageView
android:layout_width="240dp"
android:layout_height="#dimen/abc_action_bar_default_height_material"
android:layout_marginTop="98dp"
android:layout_marginRight="170dp"
android:src="#drawable/logo"
android:id="#+id/logo" />
</RelativeLayout>
Is there a way to place the black shape between the RelativeLayout and the widgets, and then set some alpha value to the black shape in order to achieve the dimming effect?
Is there a way to place the black shape between the RelativeLayout and
the widgets, and then set some alpha value to the black shape in order
to achieve the dimming effect?
You can achieve this by adding another View in your RelativeLayout and set its width and height to "match_parent", then change the View's background color to what you want.
Your layout may go like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
...
>
<View android:width="match_parent"
android:height="match_parent"
android:background="#color/the_color_you_want"/>
<here are the widgets...>
</RelativeLayout>
Update:
But it doesnt fill the entire view port, the there's about 10dp margin
on each side, that doesnt stretches across the screen. Any way to fill
the entire screen?
It's because you have set a 10dp padding for both the left and right side of your RelativeLayout. There are two ways to make the color View fill the entire screen:
Set android:clipToPadding="false" to your RelativeLayout and then set the following attribute to the color View:
android:layout_marginLeft="-10dp"
android:layout_marginRight="-10dp"
This is very easy to do but it may cause problem to your widgets, so you can have a try.
Remove paddingLeft and paddingRight attribute from your RelativeLayout, thus your color View will fill the screen, then rearrange your widgets to make sure their left or right margin is correct.
You may need to do more work with this method, but I'm sure this is a right way.
Margins in group layouts do not seem to work.
For example,
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_margin="40dip"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="#+id/button"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="I'm a button" />
</LinearLayout>
should display a button with 40p margins on all sides. However, it has 80p margins on the right and bottom.
Am I doing something wrong?
Is this a bug?
A workaround would be to use gravity, but this only works with even margins.
BTW, there is a similar question posted here but has not been answered.
android:padding="40dp" on the LinearLayout or android:layout_margin="40dp" on the Button will give you the effect you want. Padding defines the space between a views edges and its content, layout margin defines extra space on the sides of a view.
The problem is actually the way FrameLayout interprets margins. setContentView() attaches your "main" layout to a FrameLayout, which is the actual root of the view hierarchy (you can see that with Hierarchy Viewer) and is offered to you by the phone.
Margins are managed by the parent layout, so in this case that main FrameLayout. I don't know if it's a feature or a bug, but that's how this layout interprets margins.
So well, the solution was already posted while I was typing: use padding instead.
if you need set margin for a layout, simply wrap it with another linear or relative layout
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout android:layout_margin="40dip"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button android:id="#+id/button"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="I'm a button" />
</LinearLayout>
</LinearLayout>
Wrapping the Linear Layout with another layout is the best strategy.