Android Learning Series (39)-Android theme and style System (Part 1)

[Source code analysis based on the latest Android4.4]

Every company or every mobile team wants to develop its own UI framework and integrate its own design and features. This will inevitably modify the android ui.
Therefore, learning and understanding android's UI design is the most basic and necessary.
The most important part of android UI design is themes and styles.

1. Location
There are several files in the frameworks/base/core/res/values directory of Android:

themes.xmlthemes_device_defaults.xmlstyles.xmlstyles_device_defaults.xml

Various Theme and Style systems are defined respectively.

2. Theme
Focus on the themes. xml and themes_device_defaults.xml files.
Themes. xml defines theme and Holo theme in earlier versions of android, themes_device_defaults.xml defines the DeviceDefault topic (inherited from the Holo topic), and is actually customized on the Holo topic (For vendor ).
How does the system select the default topic?

    /**frameworks/base/core/java/android/content/res/Resources.java*/    /** @hide */    public static int selectDefaultTheme(int curTheme, int targetSdkVersion) {        return selectSystemTheme(curTheme, targetSdkVersion,                com.android.internal.R.style.Theme,                com.android.internal.R.style.Theme_Holo,                com.android.internal.R.style.Theme_DeviceDefault);    }            /** @hide */    public static int selectSystemTheme(int curTheme, int targetSdkVersion,            int orig, int holo, int deviceDefault) {        if (curTheme != 0) {             return curTheme;        }            if (targetSdkVersion < Build.VERSION_CODES.HONEYCOMB) {            // < 11            return orig;        }            if (targetSdkVersion < Build.VERSION_CODES.ICE_CREAM_SANDWICH) {             // < 14             return holo;        }            return deviceDefault;    }

The topic of earlier versions is used when <11, and when >=11 & <14, the topic of Holo is used.> 14, the topic of DeviceDefault is used.
For ease of understanding, we will list all the current version numbers and take a look at the history of android:

    public static class VERSION_CODES {        /**          * Magic version number for a current development build, which has         * not yet turned into an official release.         */        public static final int CUR_DEVELOPMENT = 10000;            /**          * October 2008: The original, first, version of Android.  Yay!         */        public static final int BASE = 1;            /**          * February 2009: First Android update, officially called 1.1.         */        public static final int BASE_1_1 = 2;            /**          * May 2009: Android 1.5.         */        public static final int CUPCAKE = 3;        /**          * September 2009: Android 1.6.         */        public static final int DONUT = 4;        /**         * November 2009: Android 2.0         */        public static final int ECLAIR = 5;        /**         * December 2009: Android 2.0.1         */        public static final int ECLAIR_0_1 = 6;        /**         * January 2010: Android 2.1         */        public static final int ECLAIR_MR1 = 7;        /**         * June 2010: Android 2.2         */        public static final int FROYO = 8;        /**         * November 2010: Android 2.3         */        public static final int GINGERBREAD = 9;        /**         * February 2011: Android 2.3.3.         */        public static final int GINGERBREAD_MR1 = 10;        /**         * February 2011: Android 3.0.         */        public static final int HONEYCOMB = 11;        /**         * May 2011: Android 3.1.         */        public static final int HONEYCOMB_MR1 = 12;        /**         * June 2011: Android 3.2.         */        public static final int HONEYCOMB_MR2 = 13;                /**         * October 2011: Android 4.0.         */        public static final int ICE_CREAM_SANDWICH = 14;        /**         * December 2011: Android 4.0.3.         */        public static final int ICE_CREAM_SANDWICH_MR1 = 15;        /**         * June 2012: Android 4.1.         */        public static final int JELLY_BEAN = 16;        /**         * Android 4.2: Moar jelly beans!         */        public static final int JELLY_BEAN_MR1 = 17;        /**         * Android 4.3: Jelly Bean MR2, the revenge of the beans.         */        public static final int JELLY_BEAN_MR2 = 18;        /**         * Android 4.4: KitKat, another tasty treat.         */        public static final int KITKAT = 19;    }　　

3. system Theme list
By default, the system has three major themes: Theme, Theme. Holo, and Theme. DeviceDefault. However, in fact, a large number of derived themes are defined in the basic system. The most typical Theme is the corresponding Light topic.
In addition, there are many other examples listed here. Typing is too painful. I posted:

After learning about the theme defined by the android system, we can use these theme in our own applications according to the actual situation. However, if you want to modify some theme content, you need to go further.

4. Define the item category in each topic.
What should I define for a complete topic? Take Theme as an example, as follows:
1) color

        <item name="colorForeground">@android:color/bright_foreground_dark</item>        <item name="colorForegroundInverse">@android:color/bright_foreground_dark_inverse</item>        <item name="colorBackground">@android:color/background_dark</item>        <item name="colorBackgroundCacheHint">?android:attr/colorBackground</item>        <item name="colorPressedHighlight">@color/legacy_pressed_highlight</item>        <item name="colorLongPressedHighlight">@color/legacy_long_pressed_highlight</item>        <item name="colorFocusedHighlight">@color/legacy_selected_highlight</item>        <item name="colorMultiSelectHighlight">@color/legacy_selected_highlight</item>        <item name="colorActivatedHighlight">@color/legacy_selected_highlight</item>

2) font

        <!-- Text styles -->        <item name="textAppearance">@android:style/TextAppearance</item>        <item name="textAppearanceInverse">@android:style/TextAppearance.Inverse</item>        <item name="textColorPrimary">@android:color/primary_text_dark</item>        <item name="textColorSecondary">@android:color/secondary_text_dark</item>        <item name="textColorTertiary">@android:color/tertiary_text_dark</item>        <item name="textColorPrimaryInverse">@android:color/primary_text_light</item>        <item name="textColorSecondaryInverse">@android:color/secondary_text_light</item>        <item name="textColorTertiaryInverse">@android:color/tertiary_text_light</item>        <item name="textColorPrimaryDisableOnly">@android:color/primary_text_dark_disable_only</item>        <item name="textColorPrimaryInverseDisableOnly">@android:color/primary_text_light_disable_only</item>        <item name="textColorPrimaryNoDisable">@android:color/primary_text_dark_nodisable</item>        <item name="textColorSecondaryNoDisable">@android:color/secondary_text_dark_nodisable</item>        <item name="textColorPrimaryInverseNoDisable">@android:color/primary_text_light_nodisable</item>        <item name="textColorSecondaryInverseNoDisable">@android:color/secondary_text_light_nodisable</item>        <item name="textColorHint">@android:color/hint_foreground_dark</item>        <item name="textColorHintInverse">@android:color/hint_foreground_light</item>        <item name="textColorSearchUrl">@android:color/search_url_text</item>        <item name="textColorHighlight">@android:color/highlighted_text_dark</item>        <item name="textColorHighlightInverse">@android:color/highlighted_text_light</item>        <item name="textColorLink">@android:color/link_text_dark</item>        <item name="textColorLinkInverse">@android:color/link_text_light</item>        <item name="textColorAlertDialogListItem">@android:color/primary_text_light_disable_only</item>        <item name="textAppearanceLarge">@android:style/TextAppearance.Large</item>        <item name="textAppearanceMedium">@android:style/TextAppearance.Medium</item>        <item name="textAppearanceSmall">@android:style/TextAppearance.Small</item>        <item name="textAppearanceLargeInverse">@android:style/TextAppearance.Large.Inverse</item>        <item name="textAppearanceMediumInverse">@android:style/TextAppearance.Medium.Inverse</item>        <item name="textAppearanceSmallInverse">@android:style/TextAppearance.Small.Inverse</item>        <item name="textAppearanceSearchResultTitle">@android:style/TextAppearance.SearchResult.Title</item>        <item name="textAppearanceSearchResultSubtitle">@android:style/TextAppearance.SearchResult.Subtitle</item>        <item name="textAppearanceEasyCorrectSuggestion">@android:style/TextAppearance.EasyCorrectSuggestion</item>        <item name="textAppearanceMisspelledSuggestion">@android:style/TextAppearance.MisspelledSuggestion</item>        <item name="textAppearanceAutoCorrectionSuggestion">@android:style/TextAppearance.AutoCorrectionSuggestion</item>        <item name="textAppearanceButton">@android:style/TextAppearance.Widget.Button</item>                <item name="editTextColor">@android:color/primary_text_light</item>        <item name="editTextBackground">@android:drawable/edit_text</item>                <item name="candidatesTextStyleSpans">@android:string/candidates_style</item>                <item name="textCheckMark">@android:drawable/indicator_check_mark_dark</item>        <item name="textCheckMarkInverse">@android:drawable/indicator_check_mark_light</item>        <item name="textAppearanceLargePopupMenu">@android:style/TextAppearance.Widget.PopupMenu.Large</item>        <item name="textAppearanceSmallPopupMenu">@android:style/TextAppearance.Widget.PopupMenu.Small</item>

3) button

        <!-- Button styles -->        <item name="buttonStyle">@android:style/Widget.Button</item>        <item name="buttonStyleSmall">@android:style/Widget.Button.Small</item>        <item name="buttonStyleInset">@android:style/Widget.Button.Inset</item>        <item name="buttonStyleToggle">@android:style/Widget.Button.Toggle</item>        <item name="selectableItemBackground">@android:drawable/item_background</item>        <item name="borderlessButtonStyle">?android:attr/buttonStyle</item>        <item name="homeAsUpIndicator">@android:drawable/ic_ab_back_holo_dark</item>

4) List

        <!-- List attributes -->        <item name="listPreferredItemHeight">64dip</item>        <item name="listPreferredItemHeightSmall">?android:attr/listPreferredItemHeight</item>        <item name="listPreferredItemHeightLarge">?android:attr/listPreferredItemHeight</item>        <item name="dropdownListPreferredItemHeight">?android:attr/listPreferredItemHeight</item>        <item name="textAppearanceListItem">?android:attr/textAppearanceLarge</item>        <item name="textAppearanceListItemSmall">?android:attr/textAppearanceLarge</item>        <item name="listPreferredItemPaddingLeft">6dip</item>        <item name="listPreferredItemPaddingRight">6dip</item>        <item name="listPreferredItemPaddingStart">6dip</item>        <item name="listPreferredItemPaddingEnd">6dip</item>

5) Window

        <!-- Window attributes -->        <item name="windowBackground">@android:drawable/screen_background_selector_dark</item>        <item name="windowFrame">@null</item>        <item name="windowNoTitle">false</item>        <item name="windowFullscreen">false</item>        <item name="windowOverscan">false</item>        <item name="windowIsFloating">false</item>        <item name="windowContentOverlay">@null</item>        <item name="windowShowWallpaper">false</item>        <item name="windowTitleStyle">@android:style/WindowTitle</item>        <item name="windowTitleSize">25dip</item>        <item name="windowTitleBackgroundStyle">@android:style/WindowTitleBackground</item>        <item name="android:windowAnimationStyle">@android:style/Animation.Activity</item>        <item name="android:windowSoftInputMode">stateUnspecified|adjustUnspecified</item>        <item name="windowActionBar">false</item>        <item name="windowActionModeOverlay">false</item>        <item name="windowCloseOnTouchOutside">false</item>        <item name="windowTranslucentStatus">false</item>        <item name="windowTranslucentNavigation">false</item>

6) Dialog

        <!-- Dialog attributes -->        <item name="dialogTheme">@android:style/Theme.Dialog</item>        <item name="dialogTitleIconsDecorLayout">@layout/dialog_title_icons</item>        <item name="dialogCustomTitleDecorLayout">@layout/dialog_custom_title</item>        <item name="dialogTitleDecorLayout">@layout/dialog_title</item>

7) AlertDialog

        <!-- AlertDialog attributes -->        <item name="alertDialogTheme">@android:style/Theme.Dialog.Alert</item>        <item name="alertDialogStyle">@android:style/AlertDialog</item>        <item name="alertDialogCenterButtons">true</item>        <item name="alertDialogIcon">@android:drawable/ic_dialog_alert</item>

8) Panel

        <!-- Panel attributes -->        <item name="panelBackground">@android:drawable/menu_background</item>        <item name="panelFullBackground">@android:drawable/menu_background_fill_parent_width</item>        <!-- These three attributes do not seems to be used by the framework. Declared public though -->        <item name="panelColorBackground">#000</item>        <item name="panelColorForeground">?android:attr/textColorPrimary</item>        <item name="panelTextAppearance">?android:attr/textAppearance</item>        <item name="panelMenuIsCompact">false</item>        <item name="panelMenuListWidth">296dip</item>

9) scroll bar (Scrollbar)

        <!-- Scrollbar attributes -->        <item name="scrollbarFadeDuration">250</item>        <item name="scrollbarDefaultDelayBeforeFade">300</item>         <item name="scrollbarSize">10dip</item>        <item name="scrollbarThumbHorizontal">@android:drawable/scrollbar_handle_horizontal</item>        <item name="scrollbarThumbVertical">@android:drawable/scrollbar_handle_vertical</item>        <item name="scrollbarTrackHorizontal">@null</item>        <item name="scrollbarTrackVertical">@null</item>

10) Text selection)

        <!-- Text selection handle attributes -->        <item name="textSelectHandleLeft">@android:drawable/text_select_handle_left</item>        <item name="textSelectHandleRight">@android:drawable/text_select_handle_right</item>        <item name="textSelectHandle">@android:drawable/text_select_handle_middle</item>        <item name="textSelectHandleWindowStyle">@android:style/Widget.TextSelectHandle</item>        <item name="textEditPasteWindowLayout">@android:layout/text_edit_paste_window</item>        <item name="textEditNoPasteWindowLayout">@android:layout/text_edit_no_paste_window</item>        <item name="textEditSidePasteWindowLayout">@android:layout/text_edit_side_paste_window</item>        <item name="textEditSideNoPasteWindowLayout">@android:layout/text_edit_side_no_paste_window</item>        <item name="textSuggestionsWindowStyle">@android:style/Widget.TextSuggestionsPopupWindow</item>        <item name="textEditSuggestionItemLayout">@android:layout/text_edit_suggestion_item</item>        <item name="textCursorDrawable">@null</item>

It's a little long. I will continue to list it in the next article and analyze the specific style in depth.