android桌面文件夹美化

                          By 何明桂（http://blog.csdn.net/hmg25） 转载请注明出处 

    哈哈，好久没有写博客拉，blog里边好凄凉阿~~人也变懒了……

    android原生自带的桌面文件夹样式及其简单，没有iphone那种可以显示文件夹内文件图标缩略图的功能，今天我们来简单的实现一个。

效果如下：

 

从launcher源码中很容易变可以看出需要修改的文件，主要修改FolderIcon.java这个文件。修改后的代码如下：

public class FolderIcon extends BubbleTextView implements DropTarget { private UserFolderInfo mInfo; private Launcher mLauncher; private Drawable mCloseIcon; private Drawable mOpenIcon; // add by hmg for FolderIcon { private IconCache mIconCache; private static final int ICON_COUNT = 4; //可显示的缩略图数 private static final int NUM_COL = 2; // 每行显示的个数 private static final int PADDING = 1; //内边距 private static final int MARGIN = 7; //外边距 // add by hmg for FolderIcon } public FolderIcon(Context context, AttributeSet attrs) { super(context, attrs); mIconCache = ((LauncherApplication) mContext.getApplicationContext()) .getIconCache(); } public FolderIcon(Context context) { super(context); mIconCache = ((LauncherApplication) mContext.getApplicationContext()) .getIconCache(); } static FolderIcon fromXml(int resId, Launcher launcher, ViewGroup group, UserFolderInfo folderInfo) { FolderIcon icon = (FolderIcon) LayoutInflater.from(launcher).inflate( resId, group, false); // final Resources resources = launcher.getResources(); // Drawable d = resources.getDrawable(R.drawable.ic_launcher_folder); // icon.mCloseIcon = d; // icon.mOpenIcon = // resources.getDrawable(R.drawable.ic_launcher_folder_open); // icon.setCompoundDrawablesWithIntrinsicBounds(null, d, null, null); icon.setText(folderInfo.title); icon.setTag(folderInfo); icon.setOnClickListener(launcher); icon.mInfo = folderInfo; icon.mLauncher = launcher; icon.updateFolderIcon(); //更新图标 folderInfo.setFolderIcon(icon); //设置FolderIcon return icon; } // add by hmg25 for FolderIcon { /** * Author : hmg25 Version: 1.0 Description : 更新FolderIcon显示的文件缩略图 */ public void updateFolderIcon() { float x, y; final Resources resources = mLauncher.getResources(); Bitmap closebmp = BitmapFactory.decodeResource(resources, R.drawable.icon_folder); //获取FolderIcon关闭时的背景图 Bitmap openbmp = BitmapFactory.decodeResource(resources, R.drawable.icon_folder_open); //获取FolderIcon打开时的背景图 int iconWidth = closebmp.getWidth(); //icon的宽度 int iconHeight = closebmp.getHeight(); Bitmap folderclose = Bitmap.createBitmap(iconWidth, iconHeight, Bitmap.Config.ARGB_8888); Bitmap folderopen = Bitmap.createBitmap(iconWidth, iconHeight, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(folderclose); canvas.drawBitmap(closebmp, 0, 0, null); //绘制背景 Matrix matrix = new Matrix(); // 创建操作图片用的Matrix对象 float scaleWidth = (iconWidth - MARGIN * 2) / NUM_COL - 2 * PADDING; //计算缩略图的宽(高与宽相同) float scale = (scaleWidth / iconWidth); // 计算缩放比例 matrix.postScale(scale, scale); // 设置缩放比例 for (int i = 0; i < ICON_COUNT; i++) { if (i < mInfo.contents.size()) { x = MARGIN + PADDING * (2 * (i % NUM_COL) + 1) + scaleWidth * (i % NUM_COL); y = MARGIN + PADDING * (2 * (i / NUM_COL) + 1) + scaleWidth * (i / NUM_COL); ShortcutInfo scInfo = (ShortcutInfo) mInfo.contents.get(i); Bitmap iconbmp = scInfo.getIcon(mIconCache); //获取缩略图标 Bitmap scalebmp = Bitmap.createBitmap(iconbmp, 0, 0, iconWidth, iconHeight, matrix, true); canvas.drawBitmap(scalebmp, x, y, null); } } mCloseIcon = new FastBitmapDrawable(folderclose); //将bitmap转换为Drawable setCompoundDrawablesWithIntrinsicBounds(null, mCloseIcon, null, null); canvas = new Canvas(folderopen); canvas.drawBitmap(folderclose, 0, 0, null); canvas.drawBitmap(openbmp, 0, 0, null); mOpenIcon = new FastBitmapDrawable(folderopen); //绘制open图片 } // add by hmg25 for FolderIcon } public boolean acceptDrop(DragSource source, int x, int y, int xOffset, int yOffset, DragView dragView, Object dragInfo) { final ItemInfo item = (ItemInfo) dragInfo; final int itemType = item.itemType; return (itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION || itemType == LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT) && item.container != mInfo.id; } public Rect estimateDropLocation(DragSource source, int x, int y, int xOffset, int yOffset, DragView dragView, Object dragInfo, Rect recycle) { return null; } public void onDrop(DragSource source, int x, int y, int xOffset, int yOffset, DragView dragView, Object dragInfo) { ShortcutInfo item; if (dragInfo instanceof ApplicationInfo) { // Came from all apps -- make a copy item = ((ApplicationInfo) dragInfo).makeShortcut(); } else { item = (ShortcutInfo) dragInfo; } mInfo.add(item); LauncherModel.addOrMoveItemInDatabase(mLauncher, item, mInfo.id, 0, 0, 0); updateFolderIcon(); //拖拽放入时更新 } public void onDragEnter(DragSource source, int x, int y, int xOffset, int yOffset, DragView dragView, Object dragInfo) { setCompoundDrawablesWithIntrinsicBounds(null, mOpenIcon, null, null); } public void onDragOver(DragSource source, int x, int y, int xOffset, int yOffset, DragView dragView, Object dragInfo) { } public void onDragExit(DragSource source, int x, int y, int xOffset, int yOffset, DragView dragView, Object dragInfo) { setCompoundDrawablesWithIntrinsicBounds(null, mCloseIcon, null, null); } }  

 

将文件拖拽进入文件夹时响应FolderIcon中的onDrop,所以添加updateFolderIcon();

以上代码可以实现将图标拖拽进文件夹时实时更新缩略图显示，还没有对拖拽出文件夹时更新显示，所以还需要修改其他地方。跟踪代码可以看出拖拽离开文件夹时响应UserFolder中方法onDropCompleted，需要修改UserFolder.java：

public void onDropCompleted(View target, boolean success) { if (success) { ShortcutsAdapter adapter = (ShortcutsAdapter)mContent.getAdapter(); adapter.remove(mDragItem); ((UserFolderInfo)mInfo).mFolderIcon.updateFolderIcon(); //add by hmg25 拖拽离开时更新 } } public void onDrop(DragSource source, int x, int y, int xOffset, int yOffset, DragView dragView, Object dragInfo) { ShortcutInfo item; if (dragInfo instanceof ApplicationInfo) { // Came from all apps -- make a copy item = ((ApplicationInfo)dragInfo).makeShortcut(); } else { item = (ShortcutInfo)dragInfo; } ((ShortcutsAdapter)mContent.getAdapter()).add(item); LauncherModel.addOrMoveItemInDatabase(mLauncher, item, mInfo.id, 0, 0, 0); ((UserFolderInfo)mInfo).mFolderIcon.updateFolderIcon(); //add by hmg25 将文件直接拖拽到打开的文件夹更新 }  

 

从以上代码可以看出为了传递FolderIcon对象，所以我们还需要为UserFolderInfo添加一个mFolderIcon成员，修改UserFolderInfo.java:

 protected FolderIcon mFolderIcon = null; //add by hmg25 for Folder //add by hmg25 for Folder { void setFolderIcon(FolderIcon icon) { mFolderIcon=icon; } //add by hmg25 for Folder }  

 

以上代码是在android2.2, 480*320下测试的，其他分辨率的可以修改

   private static final int ICON_COUNT = 4;  //可显示的缩略图数

    private static final int NUM_COL = 2;    // 每行显示的个数

    private static final int PADDING = 1;    //内边距

    private static final int MARGIN = 7;     //外边距

的值。