怎么去推广一个网站,网站布局策划的流程图,网站建设栏目分析,电脑网站Launcher3 一键改变Icon Shape 原理浅析 在Android O Launcher3 Google 团队增加了一个新特性#xff0c;可以在设置里面更改 桌面Icon 形状#xff0c;分别可以改为系统默认、方形、方圆形、圆形、泪珠形。 在Android P Launcher3 Google团队继续保持这一神奇特性#xff0…Launcher3 一键改变Icon Shape 原理浅析 在Android O Launcher3 Google 团队增加了一个新特性可以在设置里面更改 桌面Icon 形状分别可以改为系统默认、方形、方圆形、圆形、泪珠形。 在Android P Launcher3 Google团队继续保持这一神奇特性那么看上去好高大上神奇的特性是怎样实现的呢带着这个疑问follow me》》》》》 下面我们基于Android P Launcher3 分析Launcher3 实现基本原理。一.先看桌面设置中的菜单实现
源码位置 Launcher3\src\com\android\launcher3\SettingsActivity.javaPreference iconShapeOverride findPreference(IconShapeOverride.KEY_PREFERENCE);if (iconShapeOverride ! null) {if (IconShapeOverride.isSupported(getActivity())) {IconShapeOverride.handlePreferenceUi((ListPreference) iconShapeOverride);} else {getPreferenceScreen().removePreference(iconShapeOverride);}}可以看到isSupported方法是是否支持设置图标形状的判断条件。
public static boolean isSupported(Context context) { if (!Utilities.ATLEAST_OREO) {return false;}// Only supported when developer settings is enabledif (Settings.Global.getInt(context.getContentResolver(),Settings.Global.DEVELOPMENT_SETTINGS_ENABLED, 0) ! 1) {return false;}try {if (getSystemResField().get(null) ! Resources.getSystem()) {// Our assumption that mSystem is the system resource is not true.return false;}} catch (Exception e) {// Ignore, not supportedreturn false;}return getConfigResId() ! 0;
}由源码 可以看出 满足几个条件才能看到设置选项 1.判断系统SDK 版本是否26
2.是否打开了开发者选项。如果开发者选项没打开就看不到这个菜单。至于为神马开发者模式才可以看到待追踪可能让厂商在适配此特性吧
3.大概意思就是获取不到mSystem如果获取不到说明当前系统存在问题。
二.菜单出现后我们选择其中一种形状来设置
string-array translatablefalse nameicon_shape_override_paths_valuesitem/itemitemM50,0L100,0 100,100 0,100 0,0z/itemitemM50,0 C10,0 0,10 0,50 0,90 10,100 50,100 90,100 100,90 100,50 100,10 90,0 50,0 Z/itemitemM50 0A50 50,0,1,1,50 100A50 50,0,1,1,50 0/itemitemM50,0A50,50,0,0 1 100,50 L100,85 A15,15,0,0 1 85,100 L50,100 A50,50,0,0 1 50,0z/item
/string-arraystring-array translatablefalse nameicon_shape_override_paths_names!-- Option to not change the icon shape on home screen. [CHAR LIMIT50] --itemstring/icon_shape_system_default/itemitemSquare/itemitemSquircle/itemitemCircle/itemitemTeardrop/item
/string-array发现每个Item对应一个path 矢量图的string值。
private static class PreferenceChangeHandler implements OnPreferenceChangeListener { private final Context mContext;private PreferenceChangeHandler(Context context) {mContext context;}Overridepublic boolean onPreferenceChange(Preference preference, Object o) {String newValue (String) o;if (!getAppliedValue(mContext).equals(newValue)) {// Value has changedProgressDialog.show(mContext,null /* title */,mContext.getString(R.string.icon_shape_override_progress),true /* indeterminate */,false /* cancelable */);new LooperExecuter(LauncherModel.getWorkerLooper()).execute(new OverrideApplyHandler(mContext, newValue));}return false;}
}private static class OverrideApplyHandler implements Runnable { private final Context mContext;private final String mValue;private OverrideApplyHandler(Context context, String value) {mContext context;mValue value;}Overridepublic void run() {// Synchronously write the preference.prefs(mContext).edit().putString(KEY_PREFERENCE, mValue).commit();// Clear the icon cache.LauncherAppState.getInstance(mContext).getIconCache().clear();// Wait for ittry {Thread.sleep(PROCESS_KILL_DELAY_MS);} catch (Exception e) {Log.e(TAG, Error waiting, e);}// Schedule an alarm before we kill ourself.Intent homeIntent new Intent(Intent.ACTION_MAIN).addCategory(Intent.CATEGORY_HOME).setPackage(mContext.getPackageName()).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);PendingIntent pi PendingIntent.getActivity(mContext, RESTART_REQUEST_CODE,homeIntent, PendingIntent.FLAG_CANCEL_CURRENT | PendingIntent.FLAG_ONE_SHOT);mContext.getSystemService(AlarmManager.class).setExact(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime() 50, pi);// Kill processandroid.os.Process.killProcess(android.os.Process.myPid());}
}设置的时候执行上面代码主要将设置的保存到本地清除图标缓存然后kill Launcher process 重启launcher。
三.怎样通过矢量图工作的
源码位置 Launcher3\src\com\android\launcher3\graphics\IconShapeOverride.java
IconShapeOverride.apply(getContext());private static int getConfigResId() { return Resources.getSystem().getIdentifier(config_icon_mask, string, android);
}public static void apply(Context context) { if (!Utilities.isAtLeastO()) {return;}String path getAppliedValue(context);if (TextUtils.isEmpty(path)) {return;}if (!isSupported(context)) {return;}// magictry {Resources override new ResourcesOverride(Resources.getSystem(), getConfigResId(), path);getSystemResField().set(null, override);} catch (Exception e) {Log.e(TAG, Unable to override icon shape, e);// revert value.prefs(context).edit().remove(KEY_PREFERENCE).apply();}
}其中ResourcesOverride是继承了Resources并且重写了getString方法。 private static class ResourcesOverride extends Resources { private final int mOverrideId;private final String mOverrideValue;SuppressWarnings(deprecated)public ResourcesOverride(Resources parent, int overrideId, String overrideValue) {super(parent.getAssets(), parent.getDisplayMetrics(), parent.getConfiguration());mOverrideId overrideId;mOverrideValue overrideValue;}NonNullOverridepublic String getString(int id) throws NotFoundException {if (id mOverrideId) {return mOverrideValue;}return super.getString(id);}
}在根据源码看下getSystemResField方法
private static Field getSystemResField() throws Exception {
Field staticField Resources.class.getDeclaredField(mSystem);
staticField.setAccessible(true);
return staticField;
}
这个方法是反射系统Resources中mSystem变量。
小结
从Launcher 源代码可以看出大概的意思就是Launcher中将Resources 的mSystem设置成了ResourcesOverride对象 也就是说Resources的getSystem方法获取的是我们重写的ResourcesOverride当调用getString方法的时候走的也是重写的方法。getString方法里面判断了如果string id 是config_icon_mask这个的时候返回我们传入的mOverrideValue这个mOverrideValue就是用户选择的图标形状值。 2.pmg.jpg
追踪下 AdaptiveIconDrawable的构造方法
/** * The one constructor to rule them all. This is called by all public * constructors to set the state and initialize local properties. */
AdaptiveIconDrawable(Nullable LayerState state, Nullable Resources res) {mLayerState createConstantState(state, res);if (sMask null) {sMask PathParser.createPathFromPathData(Resources.getSystem().getString(R.string.config_icon_mask));}mMask PathParser.createPathFromPathData(Resources.getSystem().getString(R.string.config_icon_mask));mMaskMatrix new Matrix();mCanvas new Canvas();mTransparentRegion new Region();
}此方法的Resources.getSystem().getString(R.string.config_icon_mask)通过getString方法如果id是config_icon_mask则返回的是mOverrideValuemOverrideValue就是上面5种里面的一种。
四.Launcher是如何获取应用图标的:
public Drawable getFullResIcon(LauncherActivityInfo info) {
return mIconProvider.getIcon(info, mIconDpi);
}public Drawable getIcon(LauncherActivityInfo info, int iconDpi) {return info.getIcon(iconDpi);
}最终调用到LauncherActivityInfo的getIcon方法
/** * Returns the icon for this activity, without any badging for the profile * param density The preferred density of the icon, zero for default density. Use* density DPI values from {link DisplayMetrics}.* see #getBadgedIcon(int)* see DisplayMetrics* return The drawable associated with the activity.*/public Drawable getIcon(int density) {// TODO: Go through LauncherAppsServicefinal int iconRes mActivityInfo.getIconResource();Drawable icon null;// Get the preferred density icon from the apps resourcesif (density ! 0 iconRes ! 0) {try {final Resources resources mPm.getResourcesForApplication(mActivityInfo.applicationInfo);icon resources.getDrawableForDensity(iconRes, density);} catch (NameNotFoundException | Resources.NotFoundException exc) {}}// Get the default density iconif (icon null) {icon mActivityInfo.loadIcon(mPm);}return icon;
}通过以上步骤可以看出Launcher获取应用图标的时候时候如果该应用是支持AdaptiveIcon的话返回的图标就是根据形状裁剪出来的AdaptiveIconDrawableLauncher从系统拿到的图标已经是想要的形状图标了。 这就是在把launcher进程kill掉重启 launcher 重新获取加载就是被裁减过的Icon形状了
