Android Launcher源碼研究(三) 加載app流程2

接上次的。

首先Launcher實現了LauncherModel.Callbacks接口，APP信息數據加載成功後 ，回調接口把app信息顯示到Launcher的 workspace界面上，這個過程代碼裡面稱為bind。

下面是個類調用過程的時序圖，不是很標准，不過能表達基本調用順序幫助我們理解。

首先就是Launcher OnCreate中調用LauncherMode startLoader方法，這裡只看異步的方式 就是當前的頁面下標為-1，加載所有app信息

mWZ喎?/kf/ware/vc/" target="_blank" class="keylink">vcmtzcGFjZS5nZXRDdXJyZW50UGFnZSgpzqotMbXEx+m/9qGjPGJyPgogbU1vZGVsLnN0YXJ0TG9hZGVyKHRydWUsIC0xKTsgPGJyPgo8L3A+CjxwPjxicj4KPC9wPgo8cD4g1NpMYXVuY2hlck1vZGXA4LXEc3RhcnRMb2FkZXK3vbeowO/D5qOsztLDx9Do0qrKtcD9u6/P37PMwOAgTG9hZGVyVGFza6OstPOyv7fWuaTX97a81NrV4sDvw+bN6rPJLjxicj4KPC9wPgo8cD5ydW63vbeotcS0+sLro7o8L3A+CjxwPjwvcD4KPHByZSBjbGFzcz0="brush:java;"> keep_running: { // Elevate priority when Home launches for the first time to avoid // starving at boot time. Staring at a blank home is not cool. synchronized (mLock) { if (DEBUG_LOADERS) Log.d(TAG, "Setting thread priority to " + (mIsLaunching ? "DEFAULT" : "BACKGROUND")); android.os.Process.setThreadPriority(mIsLaunching ? Process.THREAD_PRIORITY_DEFAULT : Process.THREAD_PRIORITY_BACKGROUND); } if (loadWorkspaceFirst) { if (DEBUG_LOADERS) Log.d(TAG, "step 1: loading workspace"); loadAndBindWorkspace(); } else { if (DEBUG_LOADERS) Log.d(TAG, "step 1: special: loading all apps"); loadAndBindAllApps(); } if (mStopped) { break keep_running; } // Whew! Hard work done. Slow us down, and wait until the UI thread has // settled down. synchronized (mLock) { if (mIsLaunching) { if (DEBUG_LOADERS) Log.d(TAG, "Setting thread priority to BACKGROUND"); android.os.Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND); } } waitForIdle(); // second step if (loadWorkspaceFirst) { if (DEBUG_LOADERS) Log.d(TAG, "step 2: loading all apps"); loadAndBindAllApps(); } else { if (DEBUG_LOADERS) Log.d(TAG, "step 2: special: loading workspace"); loadAndBindWorkspace(); } // Restore the default thread priority after we are done loading items synchronized (mLock) { android.os.Process.setThreadPriority(Process.THREAD_PRIORITY_DEFAULT); } }
我們定位到 loadAndBindWorkspace 方法 加載workspace界面

        private void loadAndBindWorkspace() {
            mIsLoadingAndBindingWorkspace = true;

            // Load the workspace
            if (DEBUG_LOADERS) {
                Log.d(TAG, "loadAndBindWorkspace mWorkspaceLoaded=" + mWorkspaceLoaded);
            }

            if (!mWorkspaceLoaded) { //第一次加載
                loadWorkspace(); //加載
                synchronized (LoaderTask.this) {
                    if (mStopped) {
                        return;
                    }
                    mWorkspaceLoaded = true;
                }
            }

            // Bind the workspace
            bindWorkspace(-1);//綁定數據到UI
        }

loadWorkspace方法就是加載手機裡面的所有app信息，包括app widget, folder 並且存儲到ArrayList中，後面顯示這些東西到UI上。

數據我們存儲好以後調用bindWorkspace(-1)開始顯示數據到workspace，裡面包含了很多調用方法，主要是數據排序，清除以前綁定的UI數據。

在bindWorkspace方法裡面，調用了一些filter方法，這個地方主要是排序和過濾，分別判斷需要加載到那個屏幕裡面.

            r = new Runnable() {
                public void run() {
                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.startBinding();//綁定之前，清理之前的數據，簡單就這麼理解
                    }
                }
            };
            runOnMainThread(r);//UI更新需要在主線程中

下面這個方法就是把數據添加到workspace的屏幕中去.

            bindWorkspaceItems(oldCallbacks, currentWorkspaceItems, currentAppWidgets,
                    currentFolders, null);

      private void bindWorkspaceItems(final Callbacks oldCallbacks,
                final ArrayList workspaceItems,
                final ArrayList appWidgets,
                final HashMap folders,
                ArrayList deferredBindRunnables) {

            final boolean postOnMainThread = (deferredBindRunnables != null);

            // Bind the workspace items
            int N = workspaceItems.size();
            for (int i = 0; i < N; i += ITEMS_CHUNK) {
                final int start = i;
                final int chunkSize = (i+ITEMS_CHUNK <= N) ? ITEMS_CHUNK : (N-i);
                final Runnable r = new Runnable() {
                    @Override
                    public void run() {
                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                        if (callbacks != null) {
                            callbacks.bindItems(workspaceItems, start, start+chunkSize);//顯示app信息到UI上
                        }
                    }
                };
                if (postOnMainThread) {
                    deferredBindRunnables.add(r);
                } else {
                    runOnMainThread(r);
                }
            }

            // Bind the folders
            if (!folders.isEmpty()) {
                final Runnable r = new Runnable() {
                    public void run() {
                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                        if (callbacks != null) {
                            callbacks.bindFolders(folders);//顯示folders
                        }
                    }
                };
                if (postOnMainThread) {
                    deferredBindRunnables.add(r);
                } else {
                    runOnMainThread(r);
                }
            }

            // Bind the widgets, one at a time
            N = appWidgets.size();
            for (int i = 0; i < N; i++) {
                final LauncherAppWidgetInfo widget = appWidgets.get(i);
                final Runnable r = new Runnable() {
                    public void run() {
                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                        if (callbacks != null) {
                            callbacks.bindAppWidget(widget);//綁定AppWidget信息
                        }
                    }
                };
                if (postOnMainThread) {
                    deferredBindRunnables.add(r);
                } else {
                    runOnMainThread(r);
                }
            }
        }

我們這裡只看第一個綁定shortcut信息代碼，其他2個其實道理差不多.

    public void bindItems(ArrayList shortcuts, int start, int end) {
        setLoadOnResume();

        // Get the list of added shortcuts and intersect them with the set of shortcuts here
        Set newApps = new HashSet();
        newApps = mSharedPrefs.getStringSet(InstallShortcutReceiver.NEW_APPS_LIST_KEY, newApps);

        Workspace workspace = mWorkspace;
        for (int i = start; i < end; i++) {
            final ItemInfo item = shortcuts.get(i);

            // Short circuit if we are loading dock items for a configuration which has no dock
            if (item.container == LauncherSettings.Favorites.CONTAINER_HOTSEAT &&
                    mHotseat == null) {
                continue;
            }

            switch (item.itemType) {
                case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:
                case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:
                    ShortcutInfo info = (ShortcutInfo) item;
                    String uri = info.intent.toUri(0).toString();
                    View shortcut = createShortcut(info);
                    workspace.addInScreen(shortcut, item.container, item.screen, item.cellX,
                            item.cellY, 1, 1, false);
                    boolean animateIconUp = false;
                    synchronized (newApps) {
                        if (newApps.contains(uri)) {
                            animateIconUp = newApps.remove(uri);
                        }
                    }
                    if (animateIconUp) {
                        // Prepare the view to be animated up
                        shortcut.setAlpha(0f);
                        shortcut.setScaleX(0f);
                        shortcut.setScaleY(0f);
                        mNewShortcutAnimatePage = item.screen;
                        if (!mNewShortcutAnimateViews.contains(shortcut)) {
                            mNewShortcutAnimateViews.add(shortcut);
                        }
                    }
                    break;
                case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
                    FolderIcon newFolder = FolderIcon.fromXml(R.layout.folder_icon, this,
                            (ViewGroup) workspace.getChildAt(workspace.getCurrentPage()),
                            (FolderInfo) item, mIconCache);
                    workspace.addInScreen(newFolder, item.container, item.screen, item.cellX,
                            item.cellY, 1, 1, false);
                    break;
            }
        }

        workspace.requestLayout();
    }

重點就是下面這個，把數據畫到UI上面，坐標信息，APP信息.

                    workspace.addInScreen(shortcut, item.container, item.screen, item.cellX,
                            item.cellY, 1, 1, false);

最後我們調用 finishBindingItems完成調用，這個方法裡面還包括了滑動和顯示APP動畫方法的處理。

        if (mVisible || mWorkspaceLoading) {
            Runnable newAppsRunnable = new Runnable() {
                @Override
                public void run() {
                    runNewAppsAnimation(false);
                }
            };

            boolean willSnapPage = mNewShortcutAnimatePage > -1 &&
                    mNewShortcutAnimatePage != mWorkspace.getCurrentPage();
            if (canRunNewAppsAnimation()) {
                // If the user has not interacted recently, then either snap to the new page to show
                // the new-apps animation or just run them if they are to appear on the current page
                if (willSnapPage) {
                    mWorkspace.snapToPage(mNewShortcutAnimatePage, newAppsRunnable);
                } else {
                    runNewAppsAnimation(false);
                }
            } else {
                // If the user has interacted recently, then just add the items in place if they
                // are on another page (or just normally if they are added to the current page)
                runNewAppsAnimation(willSnapPage);
            }
        }

詳細的我們到後面繼續分析。還包括具體Workspace上面的界面格子cell是怎麼設計和APP添加位置的計算問題。

若有問題，請指出，謝謝~ O(∩_∩)O~