android luancher 应用信息的传递

1.简要说明，其他部分列掉：

2.进入AllAppsList，属性data是所有应用的一个数组集合。

3.进入LauncherModel，进入onlyBindAllApps方法查看到：

  final Callbacks oldCallbacks = mCallbacks.get();
            if (oldCallbacks == null) {
                // This launcher has exited and nobody bothered to tell us.  Just bail.
                Log.w(TAG, "LoaderTask running with no launcher (onlyBindAllApps)");
                return;
            }

            // shallow copy
            final ArrayList<ApplicationInfo> list
                    = (ArrayList<ApplicationInfo>)mAllAppsList.data.clone();
            mHandler.post(new Runnable() {
                public void run() {
                    final long t = SystemClock.uptimeMillis();
                    final Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.bindAllApplications(list);
                    }
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "bound all " + list.size() + " apps from cache in "
                                + (SystemClock.uptimeMillis()-t) + "ms");
                    }
                }
            });

4.定义了一个回调，然后通过回调函数callbacks.bindAllApplications(list);

5.查找回调函数bindAllApplications，进入Launcher，找到bindAllApplications函数。

    public void bindAllApplications(final ArrayList<ApplicationInfo> apps) {
        // Remove the progress bar entirely; we could also make it GONE
        // but better to remove it since we know it's not going to be used
        View progressBar = mAppsCustomizeTabHost.
            findViewById(R.id.apps_customize_progress_bar);
        if (progressBar != null) {
            ((ViewGroup)progressBar.getParent()).removeView(progressBar);
        }
        // We just post the call to setApps so the user sees the progress bar
        // disappear-- otherwise, it just looks like the progress bar froze
        // which doesn't look great
        mAppsCustomizeTabHost.post(new Runnable() {
            public void run() {
                if (mAppsCustomizeContent != null) {
                    mAppsCustomizeContent.setApps(apps);
                }
            }
        });
    }

6.看到这句代码mAppsCustomizeContent.setApps(apps)，找到setapps方法。

 public void setApps(ArrayList<ApplicationInfo> list) {
        mApps = list;
        Collections.sort(mApps, LauncherModel.APP_NAME_COMPARATOR);
        updatePageCounts();

        // The next layout pass will trigger data-ready if both widgets and apps are set, so 
        // request a layout to do this test and invalidate the page data when ready.
        if (testDataReady()) requestLayout();
    }

7.返回Launchermodel找到比较器.(根据标题进行排序)

 private static final Collator sCollator = Collator.getInstance();
    public static final Comparator<ApplicationInfo> APP_NAME_COMPARATOR
            = new Comparator<ApplicationInfo>() {
        public final int compare(ApplicationInfo a, ApplicationInfo b) {
            int result = sCollator.compare(a.title.toString(), b.title.toString());
            if (result == 0) {
                result = a.componentName.compareTo(b.componentName);
            }
            return result;
        }
    };

8.获取总数

private void updatePageCounts() {
        mNumWidgetPages = (int) Math.ceil(mWidgets.size() /
                (float) (mWidgetCountX * mWidgetCountY));
        mNumAppsPages = (int) Math.ceil((float) mApps.size() / (mCellCountX * mCellCountY));
    }

9.一部通知显示当前页的项：

 public void syncAppsPageItems(int page, boolean immediate) {
        // ensure that we have the right number of items on the pages
        int numCells = mCellCountX * mCellCountY;
        int startIndex = page * numCells;
        int endIndex = Math.min(startIndex + numCells, mApps.size());
        PagedViewCellLayout layout = (PagedViewCellLayout) getPageAt(page);

        layout.removeAllViewsOnPage();
        ArrayList<Object> items = new ArrayList<Object>();
        ArrayList<Bitmap> images = new ArrayList<Bitmap>();
        for (int i = startIndex; i < endIndex; ++i) {
            ApplicationInfo info = mApps.get(i);
            PagedViewIcon icon = (PagedViewIcon) mLayoutInflater.inflate(
                    R.layout.apps_customize_application, layout, false);
            icon.applyFromApplicationInfo(info, true, mHolographicOutlineHelper);
            icon.setOnClickListener(this);
            icon.setOnLongClickListener(this);
            icon.setOnTouchListener(this);

            int index = i - startIndex;
            int x = index % mCellCountX;
            int y = index / mCellCountX;

            layout.addViewToCellLayout(icon, -1, i, new PagedViewCellLayout.LayoutParams(x,y, 1,1));

            items.add(info);
            images.add(info.iconBitmap);

        }