How does android style cascade? - android

I'm new to android development. And i'm confusing about the cascading mechanism of android style. If i want to set the textColor of a actionBar. I need to do it like this.
<style name="AppBaseTheme" parent="android:Theme.Holo.Light">
<!-- API 14 theme customizations can go here. -->
<item name="android:actionBarStyle">#style/MyActionBar</item>
</style>
<!-- style for the action bar backgrounds -->
<style name="MyActionBar" parent="#android:style/Widget.Holo.ActionBar">
<item name="android:background">#drawable/border</item>
<item name="android:titleTextStyle">#style/MyTheme.ActionBar.TitleTextStyle</item>
</style>
<style name="MyTheme.ActionBar.TitleTextStyle" parent="#android:style/TextAppearance.Holo.Widget.ActionBar.Title">
<item name="android:textColor">#eee</item>
</style>
this works fine!! but what i'm confusing is why the following doesn't work?
<style name="AppBaseTheme" parent="android:Theme.Holo.Light">
<!-- API 14 theme customizations can go here. -->
<item name="android:actionBarStyle">#style/MyActionBar</item>
<item name="android:textColor">#eee</item>
</style>


Styles in Android are not inherited a from wrapping/outer view (ViewGroup) to the wrapped/inner views, like in HTML. So, setting the android:textColor of AppBaseTheme doesn't affect the style of title text of action bar.
The style definition states that:
When using AppBaseTheme as the style (in this case, as the theme of the activity, or all activities of the application), use MyActionBar as actionBarStyle
When using MyActionBar as the style (in this case, as the style of the action bar), use MyTheme.ActionBar.TitleTextStyle as titleTextStyle
When using MyTheme.ActionBar.TitleTextStyle as the style (in this case, as the style of the title text), use #eee as the textColor.
As you said, "When a style is applied as a theme, every View in the Activity or application will apply each style property that it supports." However, the parent style (TextAppearance.Holo.Widget.ActionBar.Title) defines the different android:textColor, so it doesn't comply one which is defined in the theme.

Related

Android Material Chip Theme overriding

I want to customize a Material chip.
I would think this is how to do it:
<style name="AppTheme" parent="Theme.MaterialComponents.NoActionBar">
.... lots more theme stuff here
<item name="chipStyle">#style/MaterialChips</item>
<item name="chipGroupStyle">#style/MaterialChips</item>
<item name="chipStandaloneStyle">#style/MaterialChips</item>
</style>
<style name="MaterialChips" parent="Widget.MaterialComponents.Chip.Choice">
<item name="chipBackgroundColor">#color/chips</item>
</style>
None of the tags like chipStyle affect the chips. But if I set app:chipBackgroundColor="#color/chips" in xml it works.
It also works fine like this for other things like say <item name="materialAlertDialogTheme">#style/AlertDialogTheme</item>.
The material documentation (if you can call it that) is really not helping.

Your app theme is correct.
The default style used by Chip component is defined in the app theme by the chipStyle attribute.
<style name="AppTheme" parent="Theme.MaterialComponents.DayNight">
<!-- Default style for chip component -->
<item name="chipStyle">#style/Widget.MaterialComponents.Chip.Action</item>
</style>
You can customize this style using for example:
<style name="AppTheme" parent="Theme.MaterialComponents.*">
<!-- Default value for chipStyle -->
<item name="chipStyle">#style/MaterialChips</item>
</style>
<style name="MaterialChips" parent="#style/Widget.MaterialComponents.Chip.Choice">
<!-- ... -->
<item name="chipBackgroundColor">#color/chips</item>
</style>
If you specify the style attribute in your layout, this style overrides the default value.
<com.google.android.material.chip.Chip
style="#style/Widget.MaterialComponents.Chip.Entry"
.../>
In this case the Chip uses the Widget.MaterialComponents.Chip.Entry style.

if you define chip style in layout xml, chip override your theme.
It may work if you clear chip style in layout xml.

Android ActionBar not changing background color

I am trying to change the background color of my action bar but it doesnt change. My app is using the AppCompat theme if that affects anything.
Here is my theme that is being used. My app points to use this theme so that is not the problem
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light">
<item name="actionBarStyle">#style/ActionBar</item>
</style>
<!-- Action Bar Styles -->
<style name="ActionBar" parent="Widget.AppCompat.ActionBar">
<item name="android:background">#color/blue</item>
<item name="background">#color/blue</item>
</style>

In your ActionBar style, delete the android:background, only keep the background attribute. Also make sure to implement your AppTheme in the application tag or in the activities extending the action bar in your AndroidManifest.xml file. I've also added the "#style/" attribute before Widget.AppCompat since its a default style defined in the android library.
Your code should look like this :
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light">
<item name="actionBarStyle">#style/ActionBar</item>
</style>
<!-- Action Bar Styles -->
<style name="ActionBar" parent="#style/Widget.AppCompat.ActionBar">
<item name="background">#0000ff</item>
</style>

You can se this from code as well
ab.setBackgroundDrawable(new ColorDrawable(newcolor));
Just in case your xml is not working

According to this link, https://developer.android.com/reference/android/R.attr.html#background
it doesn't seem to take color resource, so you either give it a hex color value or create a drawable that uses the color you want. You could try the following alternative to see if it works.
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light">
<item name="actionBarStyle">#style/ActionBar</item>
</style>
<!-- Action Bar Styles -->
<style name="ActionBar" parent="Widget.AppCompat.ActionBar">
<item name="android:background">#0000ff</item>
<item name="background">#0000ff</item>
</style>

How to set custom ActionBar color / style?

I am using Android Navigation bar in my project,
I want to change the top color in action bar to something red, How can i do that?
I have something like this,
and i want something like this,
how can i achieve that?

You can define the color of the ActionBar (and other stuff) by creating a custom Style:
Simply edit the res/values/styles.xml file of your Android project.
For example like this:
<resources>
<style name="MyCustomTheme" parent="#android:style/Theme.Holo.Light">
<item name="android:actionBarStyle">#style/MyActionBarTheme</item>
</style>
<style name="MyActionBarTheme" parent="#android:style/Widget.Holo.Light.ActionBar">
<item name="android:background">ANY_HEX_COLOR_CODE</item>
</style>
</resources>
Then set "MyCustomTheme" as the Theme of your Activity that contains the ActionBar.
You can also set a color for the ActionBar like this:
ActionBar actionBar = getActionBar();
actionBar.setBackgroundDrawable(new ColorDrawable(Color.RED)); // set your desired color
Taken from here: How do I change the background color of the ActionBar of an ActionBarActivity using XML?

In general Android OS leverages a “theme” to allow app developers to globally apply a universal set of UI element styling parameters to Android applications as a whole, or, alternatively, to a single Activity subclass.
So there are three mainstream Android OS “system themes,” which you can specify in your Android Manifest XML file when you are developing apps for Version 3.0 and later versions
I am referring the (APPCOMPAT)support library here:--
So the three themes are
1. AppCompat Light Theme (Theme.AppCompat.Light)
AppCompat Dark Theme(Theme.AppCompat),
And a hybrid between these two ,AppCompat Light Theme with the Darker ActionBar.( Theme.AppCompat.Light.DarkActionBar)
AndroidManifest.xml and see the tag, the android theme is mentioned as:-- android:theme="#style/AppTheme"
Open the Styles.xml and we have base application theme declared there:--
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
</style>
We need to override these parent theme elements to style the action bar.
ActionBar with different color background:--
To do this we need to create a new style MyActionBar(you can give any name) with a parent reference to #style/Widget.AppCompat.Light.ActionBar.Solid.Inverse that holds the style characteristics for the Android ActionBar UI element. So definition would be
<style name="MyActionBar" parent="#style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<item name="background">#color/red</item>
</style>
And this definition we need to reference in our AppTheme, pointing to overridden ActionBar styling as--
#style/MyActionBar
Change the title bar text color (e.g black to white):--
Now to change the title text color, we need to override the parent reference parent="#style/TextAppearance.AppCompat.Widget.ActionBar.Title">
So the style definition would be
<style name="MyActionBarTitle" parent="#style/TextAppearance.AppCompat.Widget.ActionBar.Title">
<item name="android:textColor">#color/white</item>
</style>
We’ll reference this style definition inside the MyActionBar style definition, since the TitleTextStyle modification is a child element of an ActionBar parent OS UI element. So the final definition of MyActionBar style element will be
<style name="MyActionBar" parent="#style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<item name="background">#color/red</item>
<item name="titleTextStyle">#style/MyActionBarTitle</item>
</style>
SO this is the final Styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light">
<!-- This is the styling for action bar -->
<item name="actionBarStyle">#style/MyActionBar</item>
</style>
<style name="MyActionBar" parent="#style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<item name="background">#color/red</item>
<item name="titleTextStyle">#style/MyActionBarTitle</item>
</style>
<style name="MyActionBarTitle" parent="#style/TextAppearance.AppCompat.Widget.ActionBar.Title">
<item name="android:textColor">#color/white</item>
</style>
</resources>
For further ActionBar options Menu styling, refer this link

For Android 3.0 and higher only
When supporting Android 3.0 and higher only, you can define the action bar's background like this:
res/values/themes.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- the theme applied to the application or activity -->
<style name="CustomActionBarTheme" parent="#style/Theme.Holo.Light.DarkActionBar">
<item name="android:actionBarStyle">#style/MyActionBar</item>
</style>
<!-- ActionBar styles -->
<style name="MyActionBar" parent="#style/Widget.Holo.Light.ActionBar.Solid.Inverse">
<item name="android:background">#ff0000</item>
</style>
</resources>
For Android 2.1 and higher
When using the Support Library, your style XML file might look like this:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- the theme applied to the application or activity -->
<style name="CustomActionBarTheme" parent="#style/Theme.AppCompat.Light.DarkActionBar">
<item name="android:actionBarStyle">#style/MyActionBar</item>
<!-- Support library compatibility -->
<item name="actionBarStyle">#style/MyActionBar</item>
</style>
<!-- ActionBar styles -->
<style name="MyActionBar"
parent="#style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<item name="android:background">#drawable/actionbar_background</item>
<!-- Support library compatibility -->
<item name="background">#drawable/actionbar_background</item>
</style>
</resources>
Then apply your theme to your entire app or individual activities:
for more details Documentaion

You can change action bar color on this way:
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="colorPrimary">#color/green_action_bar</item>
</style>
Thats all you need for changing action bar color.
Plus if you want to change the status bar color just add the line:
<item name="android:colorPrimaryDark">#color/green_dark_action_bar</item>
Here is a screenshot taken from developer android site to make it more clear, and here is a link to read more about customizing the color palete

Another possibility of making.
actionBar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#0000ff")));

I can change ActionBar text color by using titleTextColor
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="titleTextColor">#333333</item>
</style>

Custom Color:
<style name="AppTheme" parent="Theme.AppCompat.Light">
<item name="colorPrimary">#color/ColorPrimary</item>
<item name="colorPrimaryDark">#color/ColorPrimaryDark</item>
<!-- Customize your theme here. -->
</style>
Custom Style:
<style name="Theme.AndroidDevelopers" parent="android:style/Theme.Holo.Light">
<item name="android:selectableItemBackground">#drawable/ad_selectable_background</item>
<item name="android:popupMenuStyle">#style/MyPopupMenu</item>
<item name="android:dropDownListViewStyle">#style/MyDropDownListView</item>
<item name="android:actionBarTabStyle">#style/MyActionBarTabStyle</item>
<item name="android:actionDropDownStyle">#style/MyDropDownNav</item>
<item name="android:listChoiceIndicatorMultiple">#drawable/ad_btn_check_holo_light</item>
<item name="android:listChoiceIndicatorSingle">#drawable/ad_btn_radio_holo_light</item>
</style>
For More: Android ActionBar

As I was using AppCompatActivity above answers didn't worked for me. But the below solution worked:
In res/styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
</style>
PS: I've used colorPrimary instead of android:colorPrimary

in the style.xml add this code
<resources>
<style name="MyTheme" parent="#android:style/Theme.Holo.Light">
<item name="android:actionBarStyle">#style/MyAction</item>
</style>
<style name="MyActionBarTheme" parent="#android:style/Widget.Holo.Light.ActionBar">
<item name="android:background">#333333</item>
</style>
</resources>

Use this - http://jgilfelt.github.io/android-actionbarstylegenerator/
Good tool to customize your actionbar with a live preview in couple of minutes.

android - how to remove ActionBarDivider in Holo theme

I have an Activity with a dark ActionBar. I need to remove its vertical dividers since my icons already have "built-in" dividers.
What I've tried goes below
Activity style:
<style name="sMain" parent="#android:style/Theme.Holo">
<item name="android:icon">#android:color/transparent</item>
<item name="android:actionBarStyle">#style/MyActionBar</item>
</style>
MyActionBar:
<style name="MyActionBar" parent="android:Widget.Holo.ActionBar">
<item name="android:actionBarDivider">#null</item>
</style>
This doesn't have any effect. Any ideas what I'm doing wrong?

You need to set the android:actionBarStyle attribute as part of the activity theme, not as part of the action bar style.
So I believe this should work:
<style name="sMain" parent="#android:style/Theme.Holo">
<item name="android:icon">#android:color/transparent</item>
<item name="android:actionBarStyle">#style/MyActionBar</item>
<item name="android:actionBarDivider">#null</item>
</style>
How to tell where attributes belong? I used to struggle with this too (usually solved by trial-and-error) until I discovered the use of the android.R.styleable class! Have a look here: https://developer.android.com/reference/android/R.styleable.html
If you do a search in the page for actionBarStyle you will see it shows up as Theme_actionBarStyle, meaning it is part of the Theme style (remember there is no technical difference between a theme and a style). If you do a search on ActionBar_ you will be able to iterate through all of the attributes that can be set as part of an ActionBar style.

ActionBar title color does not change

I want to change the title color of actionbar to white. I have declared on styles:
<!--
Base application theme, dependent on API level. This theme is replaced
by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
-->
<style name="AppBaseTheme" parent="android:Theme.Holo.Light">
<!--
Theme customizations available in newer API levels can go in
res/values-vXX/styles.xml, while customizations related to
backward-compatibility can go here.
-->
</style>
<!-- Application theme -->
<style name="AppTheme" parent="AppBaseTheme">
<!-- All customizations that are NOT specific to a particular API-level can go here. -->
<item name="android:windowActionBar">true</item>
<item name="android:actionBarStyle">#style/ProjActionBar</item>
<item name="android:actionBarTabTextStyle">#style/ProjActionBar.TitleTextStyle</item>
</style>
<!-- ActionBar Style -->
<style name="ProjActionBar" parent="#android:style/Widget.Holo.Light.ActionBar">
<item name="android:background">#color/b</item>
<item name="android:backgroundStacked">#color/k1</item>
<!-- This is when tabs are splitted into a second line -->
</style>
<style name="ProjActionBar.TitleTextStyle" parent="#android:style/TextAppearance">
<item name="android:textColor">#color/w</item>
<item name="android:textSize">13sp</item>
</style>
As you can see I have a "actionBarTabTextStyle" declared with the attribute "textColor" to #color/w declared in my colors.xml as:
<color name="w">#FFFFFFFF</color>
What happend? why the actionbar title does not change textColor?
My project is targeted to min SDK 11 sdkVersion 17 (Honeycomb 3.0+)

The problem is that you have not actually changed the title text style. You have changed the style of the tab text. To change the title text style, you want to set android:titleTextStyle and optionally android:subtitleTextStyle on your ProjActionBar style.
So, your ProjActionBar becomes this:
<style name="ProjActionBar" parent="#android:style/Widget.Holo.Light.ActionBar">
<item name="android:background">#color/b</item>
<item name="android:backgroundStacked">#color/k1</item>
<item name="android:titleTextStyle">#style/ProjActionBar.TitleTextStyle</item>
</style>
Please note that this assumes you are using the native ActionBar components (as indicated by the fact that you are inheriting from #android:style/Widget.Holo.Light.ActionBar). If you want backwards compatibility, you will have to inherit your style from Widget.AppCompat.Light.ActionBar and use textStyle instead of android:textStyle.

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