Android8.1 Launcher3 修改文件夹样式（一）

Android8.1 Launcher3 修改文件夹样式（一）

经过前面几天的努力，launcher看起来已经舒服多了；但是文件夹的外观还是让人不爽，不知道是不是因为美国人的审美跟我们不一样，还是Google工程师有意让我们自己修改。

这篇博客主要修改文件夹展开后的样式，博客理提到的文件夹都是展开后的文件夹。

1：首先让文件夹的大小固定

src/com/android/launcher3/folder/FolderPagedView.java -> FolderPagedView()

public FolderPagedView(Context context, AttributeSet attrs) {
        super(context, attrs);
        InvariantDeviceProfile profile = LauncherAppState.getIDP(context);
        /* 修改最大行列 begin */
//        mMaxCountX = profile.numFolderColumns;
//        mMaxCountY = profile.numFolderRows;
        mMaxCountX = 3;
        mMaxCountY = 3;
        /* 修改最大行列 0000009 end */
        ......
}

我这里就直接用固定数据代替了，其实应该用配置文件的。

再修改文件夹高度，我这里高度直接设置850：
src/com/android/launcher3/folder/Folder.java

private int getContentAreaHeight() {
        /* 修改文件夹高度 begin */
//        DeviceProfile grid = mLauncher.getDeviceProfile();
//        int maxContentAreaHeight = grid.availableHeightPx
//                - grid.getTotalWorkspacePadding().y - mFooterHeight;
//        int height = Math.min(maxContentAreaHeight,
//                mContent.getDesiredHeight());
//        return Math.max(height, MIN_CONTENT_DIMEN);
        return 850 - mFooterHeight;
        /* 修改文件夹高度 end */
    }

修改文件夹宽度
src/com/android/launcher3/folder/Folder.java

public int getDesiredWidth() {
        /* 修改文件夹宽度 begin */
//        return getPaddingLeft() + getPaddingRight() + (mCountX * mCellWidth);
        return getPaddingLeft() + getPaddingRight() + (3 * mCellWidth);
        /* 修改文件夹宽度 end */
    }

运行一下，发现文件夹的大小是固定了，但是没有在屏幕中间显示，继续搞

2：让文件夹在屏幕中间显示

这一步我走了很多冤枉路，其实很简单，几行代码就搞定
src/com/android/launcher3/folder/Folder.java -> centerAboutIcon():

private void centerAboutIcon() {

......

       } else {
            // Folder height is less than page height, so bound it to the absolute open folder
            // bounds if necessary
            Rect folderBounds = grid.getAbsoluteOpenFolderBounds();
            left = Math.max(folderBounds.left, Math.min(left, folderBounds.right - width));
            top = Math.max(folderBounds.top, Math.min(top, folderBounds.bottom - height));
        }

        int folderPivotX = width / 2 + (centeredLeft - left);
        int folderPivotY = height / 2 + (centeredTop - top);
        setPivotX(folderPivotX);
        setPivotY(folderPivotY);

        mFolderIconPivotX = (int) (mFolderIcon.getMeasuredWidth() *
                (1.0f * folderPivotX / width));
        mFolderIconPivotY = (int) (mFolderIcon.getMeasuredHeight() *
                (1.0f * folderPivotY / height));

        lp.width = width;
        lp.height = height;
        /* 修改left top begin */
//        lp.x = left;
//        lp.y = top;
        lp.x = (850 - getFolderWidth()) / 2;
        lp.y = 450;
        /* 修改left top */
}

运行一下，文件夹可以在屏幕中间显示，但是有一个问题，当文件夹中只有两个app的时候，不是靠左显示，而是居中显示的

3：文件夹内部APP靠左展示

本来以为这个应该是LayoutParams属性控制的，就去找对应的属性，但是始终没有效果；偶然跟进方法的时候，进入到
src/com/android/launcher3/CellLayout.java -> onLayout():

@Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        boolean isFullscreen = mShortcutsAndWidgets.getChildCount() > 0 &&
                ((LayoutParams) mShortcutsAndWidgets.getChildAt(0).getLayoutParams()).isFullscreen;
        int left = getPaddingLeft();
        /* 靠左展示 begin */
//        if (!isFullscreen) {
//            left += (int) Math.ceil(getUnusedHorizontalSpace() / 2f);
//        }
        /* 靠左展示 end */
        int right = r - l - getPaddingRight();
        if (!isFullscreen) {
            right -= (int) Math.ceil(getUnusedHorizontalSpace() / 2f);
        }

        int top = getPaddingTop();
        int bottom = b - t - getPaddingBottom();

        mTouchFeedbackView.layout(left, top,
                left + mTouchFeedbackView.getMeasuredWidth(),
                top + mTouchFeedbackView.getMeasuredHeight());
        mShortcutsAndWidgets.layout(left, top, right, bottom);

        // Expand the background drawing bounds by the padding baked into the background drawable
        mBackground.getPadding(mTempRect);
        mBackground.setBounds(
                left - mTempRect.left - getPaddingLeft(),
                top - mTempRect.top - getPaddingTop(),
                right + mTempRect.right + getPaddingRight(),
                bottom + mTempRect.bottom + getPaddingBottom());
    }

看到 isFullscreen 的时候，有一种解脱的感觉（终于找到地方了），顺利解决这个问题。
但是这个时候如果文件夹内有4个app，是2*2摆放的，所以再修改摆放位置：
src/com/android/launcher3/folder/FolderPagedView.java -> calculateGridSize():

public static void calculateGridSize(int count, int countX, int countY, int maxCountX,
            int maxCountY, int maxItemsPerPage, int[] out) {
        boolean done;
        int gridCountX = countX;
        int gridCountY = countY;

        if (count >= maxItemsPerPage) {
            gridCountX = maxCountX;
            gridCountY = maxCountY;
            done = true;
        } else {
            done = false;
            /* 添加新计算 begin */
            if(count >3){
                gridCountX = 3;
                gridCountY = (count+1)/4 + 1;
            }else{
                gridCountX = count;
                gridCountY =1 ;
            }
            /* 添加新计算 end */
        }
        /* 注释旧计算 begin */
//        while (!done) {
//            int oldCountX = gridCountX;
//            int oldCountY = gridCountY;
//            if (gridCountX * gridCountY < count) {
//                // Current grid is too small, expand it
//                if ((gridCountX <= gridCountY || gridCountY == maxCountY)
//                        && gridCountX < maxCountX) {
//                    gridCountX++;
//                } else if (gridCountY < maxCountY) {
//                    gridCountY++;
//                }
//                if (gridCountY == 0) gridCountY++;
//            } else if ((gridCountY - 1) * gridCountX >= count && gridCountY >= gridCountX) {
//                gridCountY = Math.max(0, gridCountY - 1);
//            } else if ((gridCountX - 1) * gridCountY >= count) {
//                gridCountX = Math.max(0, gridCountX - 1);
//            }
//            done = gridCountX == oldCountX && gridCountY == oldCountY;
//        }
        /* 注释旧计算 end */
        out[0] = gridCountX;
        out[1] = gridCountY;
    }

4：文件夹展开的时候，隐藏workspace和HotSeat

不多说，上代码
src/com/android/launcher3/folder/Folder.java -> animateOpen()：

public void animateOpen() {
......
        sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
        dragLayer.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED);
        /* 隐藏workspace和HotSeat begin */
        mLauncher.getWorkspace().setVisibility(View.GONE);
        mLauncher.getHotseat().setVisibility(View.GONE);
        /* 隐藏workspace和HotSeat 0000009 end */
    }

src/com/android/launcher3/folder/Folder.java -> handleClose()：

@Override
    protected void handleClose(boolean animate) {
        mIsOpen = false;

        if (isEditingName()) {
            mFolderName.dispatchBackKey();
        }

        if (mFolderIcon != null) {
            if (FeatureFlags.LAUNCHER3_NEW_FOLDER_ANIMATION) {
                mFolderIcon.clearLeaveBehindIfExists();
            } else {
                mFolderIcon.shrinkAndFadeIn(animate);
            }
        }

        if (!(getParent() instanceof DragLayer)) return;
        DragLayer parent = (DragLayer) getParent();

        if (animate) {
            animateClosed();
        } else {
            closeComplete(false);
        }

        // Notify the accessibility manager that this folder "window" has disappeared and no
        // longer occludes the workspace items
        parent.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
        /* 显示workspace和HotSeat begin */
        mLauncher.getWorkspace().setVisibility(View.VISIBLE);
        mLauncher.getHotseat().setVisibility(View.VISIBLE);
        /* 显示workspace和HotSeat end */
    }

总结：这几天一直在看launcher，都快看吐了，得缓几天，先看看别的模块（SystemUI，Settings，Gallery）