Android - default button style

Kajiyama picture Kajiyama · Nov 4, 2012 · Viewed 61.3k times · Source

Question: Where can I find default styles xml with hexadecimal codes of colors?

I'm looking for Style 'buttonStyle' and other default styles witch affect aspects like TextViews, Buttons etc (if you dont change the style of aspect)

I looked up in <instalation_folder>\android-sdk\platforms\android-<versio>\data\res\values and <instalation_folder>\android-sdk\platforms\android-<version>\data\res\colors but I didn't actually find what I was looking for.

Hope my question is clear.


Due to low reputation I cant answer this question yet. Here is answer

Answer

With a bit of googling I found 'buttonStyle' is actually 'Widget.Button' - Styling Android With Defaults

This is how it works:

  • As I said 'buttonStyle' style is accualy 'Widget.Button' style defined in \android-sdk\platforms\android-<version>\data\res\values\styles.xml. Background is set to: @android:drawable/btn_default
  • \android-sdk\platforms\android-<version>\data\res\drawable\btn_default.xml defines background color of button as selector. Color actually depends on button's state. Default color is set to @drawable/btn_default_normal
  • With a bit of searching I found, that btn_default_normal is png image located in \android-sdk\platforms\android-<version>\data\res\drawable-mdpi

I find it a bit confusing, but I hope it will help someone, maybe...

Answer

forgemo picture forgemo · Nov 4, 2012

Understanding how Android styles do work can be a little bit messy.

I will try to explain how the basic work flow would be, based on an example.

Let's assume you want to know what the default background for buttons is. This can be either a simple color (unlikely) or a drawable (there are many different types of drawables).

Android has Themes. A theme basically defines which style is applied to which widget. Therefore, our first step is to find the default android theme.

You find it under android-sdk\platforms\android-15\data\res\values\themes.xml

In this theme file, search for button.

You will find something like this:

<!-- Button styles -->

<item name="buttonStyle">@android:style/Widget.Button</item>

This means that the theme applies the style Widget.Button to buttons.

Ok, now let's find the style Widget.Button.

All default Android style are defined in the file android-sdk\platforms\android-15\data\res\values\styles.xml

Now search for Widget.Button

You will find something like this:

<style name="Widget.Button">
    <item name="android:background">@android:drawable/btn_default</item>
    <item name="android:focusable">true</item>
    <item name="android:clickable">true</item>
    <item name="android:textAppearance">?android:attr/textAppearanceSmallInverse</item>
    <item name="android:textColor">@android:color/primary_text_light</item>
    <item name="android:gravity">center_vertical|center_horizontal</item>
</style>

The interesting line is:

<item name="android:background">@android:drawable/btn_default</item>

This means that there is a drawable called btn_default set as button background.

Now we need to find a file named btn_default.* in one of the drawable folders under android-sdk\platforms\android-15\data\res.

This can be either an image (very unlikely) or a xml file like btn_default.xml.

After a little bit searching you will find the file android-sdk\platforms\android-15\data\res\drawable\btn_default.xml

It contains something like this:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_window_focused="false" android:state_enabled="true" android:drawable="@drawable/btn_default_normal" />
    <item android:state_window_focused="false" android:state_enabled="false" android:drawable="@drawable/btn_default_normal_disable" />
    <item android:state_pressed="true" android:drawable="@drawable/btn_default_pressed" />
    <item android:state_focused="true" android:state_enabled="true" android:drawable="@drawable/btn_default_selected" />
    <item android:state_enabled="true" android:drawable="@drawable/btn_default_normal" />
    <item android:state_focused="true" android:drawable="@drawable/btn_default_normal_disable_focused" />
    <item android:drawable="@drawable/btn_default_normal_disable" />
</selector>

Now you have to understand that this is a selector drawable (one of the many drawable types). This selector chooses different backgrounds, based on the buttons state. For example, if the buttons is pressed, it has a different background.

No let's look at the default state.

<item android:state_enabled="true" android:drawable="@drawable/btn_default_normal" />

It applies a drawable called btn_default_normal.

Now we need to find this drawable.

Again, we need to find a file named btn_default_normal.* in one of the drawable folders under android-sdk\platforms\android-15\data\res.

This can be again either an image or a xml file like btn_default_normal.xml.

You will find multiple files called 'btn_default_normal.9.png' in different drawable folders for different resolutions.

:) Now you know that btn_default_normal.9.png is set as button background.