Interchange positions of two Views within GridLayout (Android)

Question

I have programmed a basic gaming App that consists of blocks which can be exchanged by a swipe (similar to CandyCrush). I succeeded in recognizing the swipe gesture but my code that changes the positions of the Views (blocks) within a GridLayout does only work in the emulator but not on a real device (Samsung Galaxy S3).

Also I couldn't find a way of animating the interchange of the two views. I've added android:animateLayoutChanges="true" to the GridLayout XML but it didn't change anything.

Here's my exchanging code:

// change to blocks positions in grid layout
GridLayout.LayoutParams sourceParams = (GridLayout.LayoutParams)this.imageView.getLayoutParams();
GridLayout.LayoutParams targetParams = (GridLayout.LayoutParams)otherBlock.imageView.getLayoutParams();

GridLayout.Spec sourceRowSpec = sourceParams.rowSpec;
GridLayout.Spec sourceColumnSpec = sourceParams.columnSpec;
sourceParams.rowSpec = targetParams.rowSpec;
sourceParams.columnSpec = targetParams.columnSpec;
targetParams.rowSpec = sourceRowSpec;
targetParams.columnSpec = sourceColumnSpec;

this.imageView.setLayoutParams(sourceParams);
otherBlock.imageView.setLayoutParams(targetParams);

gameGridLayout.requestLayout();

And here's a screenshot of the App:

Answer 1

You should have an index table of your layout, and in your drawing method you run through this index to draw each block. Like that:

private int [][] index;

void onDraw(Canvas canvas)  {
    for (int i = 0; i < MAX_BLOCK_HEIGHT; i++)  {
        for (int j = 0; j < MAX_BLOCK_WIDTH; j++)   {
            // Draw block index[i][j]
        }
    }
}

void swapBlock(int blockX, int blockY, int relativePos) {
    int tmpBlock = index[blockY][blockX];
    if (relativePos == AT_LEFT) {
        index[blockY][blockX] = index[blockY][blockX - 1];
        index[blockY][blockX - 1] = tmpBlock;
    }
    // And so on...

}

And this index can be helpful all the time, not only for blit.