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 int availableWidth = recyclerView.getMeasuredWidth();
26                if (availableWidth == 0) {
27                    Log.e(Config.LOGTAG,"GridManager: available width was 0; probably because layout was hidden");
28                    return;
29                }
30                final ColumnInfo columnInfo = calculateColumnCount(context, recyclerView.getMeasuredWidth(), desiredSize);
31                Log.d(Config.LOGTAG, "final count " + columnInfo.count);
32                if (recyclerView.getAdapter().getItemCount() != 0) {
33                    Log.e(Config.LOGTAG, "adapter already has items; just go with it now");
34                    return;
35                }
36                setupLayoutManagerInternal(recyclerView, columnInfo);
37                MediaAdapter.setMediaSize(recyclerView, columnInfo.width);
38            }
39        });
40    }
41
42    private static void setupLayoutManagerInternal(RecyclerView recyclerView, final ColumnInfo columnInfo) {
43        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
44        if (layoutManager instanceof GridLayoutManager) {
45            ((GridLayoutManager) layoutManager).setSpanCount(columnInfo.count);
46        }
47    }
48
49    private static ColumnInfo calculateColumnCount(Context context, int availableWidth, @DimenRes int desiredSize) {
50        final float desiredWidth = context.getResources().getDimension(desiredSize);
51        final int columns = Math.round(availableWidth / desiredWidth);
52        final int realWidth = availableWidth / columns;
53        Log.d(Config.LOGTAG, "desired=" + desiredWidth + " real=" + realWidth);
54        return new ColumnInfo(columns, realWidth);
55    }
56
57    public static int getCurrentColumnCount(RecyclerView recyclerView) {
58        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
59        if (layoutManager instanceof GridLayoutManager) {
60            return ((GridLayoutManager) layoutManager).getSpanCount();
61        } else {
62            return 0;
63        }
64    }
65
66    public static class ColumnInfo {
67        private final int count;
68        private final int width;
69
70        private ColumnInfo(int count, int width) {
71            this.count = count;
72            this.width = width;
73        }
74    }
75
76}