Android launcher source code explanation 01: Ui layout details 1

This series of articles will start the android lancher source code analysis. The example is the launcher3 source code that comes with Android 2.3. Its: http://download.csdn.net/detail/xianming01/4383598

This is the first article to introduce lancher's UI layout.

1. Layout

Run the APK and the execution result is:

After pressing the Home key:

2. layout files

Let's take a look at the layout file launcher. xml of lancher. Its source code is:

<com.android.launcher3.DragLayer    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:launcher="http://schemas.android.com/apk/res/com.android.launcher3"    android:id="@+id/drag_layer"    android:layout_width="match_parent"    android:layout_height="match_parent">    <include layout="@layout/all_apps" />    <!-- The workspace contains 3 screens of cells -->    <com.android.launcher3.Workspace        android:id="@+id/workspace"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:scrollbars="horizontal"        android:fadeScrollbars="true"        launcher:defaultScreen="2">        <include android:id="@+id/cell1" layout="@layout/workspace_screen" />        <include android:id="@+id/cell2" layout="@layout/workspace_screen" />        <include android:id="@+id/cell3" layout="@layout/workspace_screen" />        <include android:id="@+id/cell4" layout="@layout/workspace_screen" />        <include android:id="@+id/cell5" layout="@layout/workspace_screen" />    </com.android.launcher3.Workspace>    <com.android.launcher3.ClippedImageView        android:id="@+id/previous_screen"        android:layout_width="93dip"        android:layout_height="@dimen/button_bar_height"        android:layout_gravity="bottom|left"        android:layout_marginLeft="6dip"        android:scaleType="center"        android:src="@drawable/home_arrows_left"                android:onClick="previousScreen"        launcher:ignoreZone="56dip"        android:focusable="true"        android:clickable="true" />    <com.android.launcher3.ClippedImageView        android:id="@+id/next_screen"        android:layout_width="93dip"        android:layout_height="@dimen/button_bar_height"        android:layout_gravity="bottom|right"        android:layout_marginRight="6dip"        android:scaleType="center"        android:src="@drawable/home_arrows_right"                android:onClick="nextScreen"                launcher:ignoreZone="-56dip"                android:focusable="true"        android:clickable="true" />    <com.android.launcher3.DeleteZone        android:id="@+id/delete_zone"        android:layout_width="@dimen/delete_zone_size"        android:layout_height="@dimen/delete_zone_size"        android:paddingLeft="@dimen/delete_zone_padding"        android:layout_marginBottom="@dimen/half_status_bar_height"        android:layout_gravity="right|center_vertical"        android:scaleType="center"        android:src="@drawable/delete_zone_selector"        android:visibility="invisible"        launcher:direction="vertical"        />    <RelativeLayout        android:id="@+id/all_apps_button_cluster"        android:layout_height="fill_parent"        android:layout_width="@dimen/button_bar_height_portrait"        android:layout_gravity="right|center_vertical"        android:layout_marginBottom="@dimen/half_status_bar_height"        >        <com.android.launcher3.HandleView            style="@style/HotseatButton"            android:id="@+id/all_apps_button"            android:layout_centerVertical="true"            android:layout_alignParentRight="true"            android:src="@drawable/all_apps_button"            launcher:direction="vertical"            />        <ImageView            android:id="@+id/hotseat_left"            style="@style/HotseatButton.Left"            android:layout_below="@id/all_apps_button"            android:src="@drawable/hotseat_phone"            android:onClick="launchHotSeat"            />        <ImageView            android:id="@+id/hotseat_right"            style="@style/HotseatButton.Right"            android:layout_above="@id/all_apps_button"            android:src="@drawable/hotseat_browser"            android:onClick="launchHotSeat"            />    </RelativeLayout></com.android.launcher3.DragLayer>

3. layout File Analysis

For each part, the image is as follows:

• The first-level UI of launcher is draglayer.

• Draglayer has several children, the most important of which is workplace and all1_2d as follows:

• Workplace has five children, each of which is a celllayout

Put widgets and application shortcuts in each celllayout (bubbletextview)

• Allcategory 2D displays the list of all applications

Reference: 4. Details about launcher UI Layout