1package eu.siacs.conversations.ui.util;
 2
 3import android.content.Context;
 4import android.support.annotation.DimenRes;
 5import android.support.v7.widget.GridLayoutManager;
 6import android.support.v7.widget.RecyclerView;
 7import android.util.Log;
 8import android.view.ViewTreeObserver;
 9
10import eu.siacs.conversations.Config;
11import eu.siacs.conversations.ui.adapter.MediaAdapter;
12
13public class GridManager {
14
15    public static void setupLayoutManager(final Context context, RecyclerView recyclerView, @DimenRes int desiredSize) {
16        int maxWidth = context.getResources().getDisplayMetrics().widthPixels;
17        ColumnInfo columnInfo = calculateColumnCount(context, maxWidth, desiredSize);
18        Log.d(Config.LOGTAG, "preliminary count=" + columnInfo.count);
19        MediaAdapter.setMediaSize(recyclerView, columnInfo.width);
20        recyclerView.setLayoutManager(new GridLayoutManager(context, columnInfo.count));
21        recyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
22            @Override
23            public void onGlobalLayout() {
24                recyclerView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
25                final ColumnInfo columnInfo = calculateColumnCount(context, recyclerView.getMeasuredWidth(), desiredSize);
26                Log.d(Config.LOGTAG, "final count " + columnInfo.count);
27                if (recyclerView.getAdapter().getItemCount() != 0) {
28                    Log.e(Config.LOGTAG, "adapter already has items; just go with it now");
29                    return;
30                }
31                setupLayoutManagerInternal(recyclerView, columnInfo);
32                MediaAdapter.setMediaSize(recyclerView, columnInfo.width);
33            }
34        });
35    }
36
37    private static void setupLayoutManagerInternal(RecyclerView recyclerView, final ColumnInfo columnInfo) {
38        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
39        if (layoutManager instanceof GridLayoutManager) {
40            ((GridLayoutManager) layoutManager).setSpanCount(columnInfo.count);
41        }
42    }
43
44    private static ColumnInfo calculateColumnCount(Context context, int availableWidth, @DimenRes int desiredSize) {
45        final float desiredWidth = context.getResources().getDimension(desiredSize);
46        final int columns = Math.round(availableWidth / desiredWidth);
47        final int realWidth = availableWidth / columns;
48        Log.d(Config.LOGTAG, "desired=" + desiredWidth + " real=" + realWidth);
49        return new ColumnInfo(columns, realWidth);
50    }
51
52    public static int getCurrentColumnCount(RecyclerView recyclerView) {
53        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
54        if (layoutManager instanceof GridLayoutManager) {
55            return ((GridLayoutManager) layoutManager).getSpanCount();
56        } else {
57            return 0;
58        }
59    }
60
61    public static class ColumnInfo {
62        private final int count;
63        private final int width;
64
65        private ColumnInfo(int count, int width) {
66            this.count = count;
67            this.width = width;
68        }
69    }
70
71}