1package eu.siacs.conversations.ui.util;
 2
 3import android.content.Context;
 4import android.util.Log;
 5import android.view.ViewTreeObserver;
 6
 7import androidx.annotation.DimenRes;
 8import androidx.recyclerview.widget.GridLayoutManager;
 9import androidx.recyclerview.widget.RecyclerView;
10
11import eu.siacs.conversations.Config;
12import eu.siacs.conversations.ui.adapter.MediaAdapter;
13
14public class GridManager {
15
16    public static void setupLayoutManager(final Context context, RecyclerView recyclerView, @DimenRes int desiredSize) {
17        int maxWidth = context.getResources().getDisplayMetrics().widthPixels;
18        ColumnInfo columnInfo = calculateColumnCount(context, maxWidth, desiredSize);
19        Log.d(Config.LOGTAG, "preliminary count=" + columnInfo.count);
20        MediaAdapter.setMediaSize(recyclerView, columnInfo.width);
21        recyclerView.setLayoutManager(new GridLayoutManager(context, columnInfo.count));
22        recyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
23            @Override
24            public void onGlobalLayout() {
25                recyclerView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
26                final int availableWidth = recyclerView.getMeasuredWidth();
27                if (availableWidth == 0) {
28                    Log.e(Config.LOGTAG,"GridManager: available width was 0; probably because layout was hidden");
29                    return;
30                }
31                final ColumnInfo columnInfo = calculateColumnCount(context, recyclerView.getMeasuredWidth(), desiredSize);
32                Log.d(Config.LOGTAG, "final count " + columnInfo.count);
33                final RecyclerView.Adapter adapter = recyclerView.getAdapter();
34                if (adapter != null && adapter.getItemCount() != 0) {
35                    Log.e(Config.LOGTAG, "adapter already has items; just go with it now");
36                    return;
37                }
38                setupLayoutManagerInternal(recyclerView, columnInfo);
39                MediaAdapter.setMediaSize(recyclerView, columnInfo.width);
40            }
41        });
42    }
43
44    private static void setupLayoutManagerInternal(RecyclerView recyclerView, final ColumnInfo columnInfo) {
45        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
46        if (layoutManager instanceof GridLayoutManager) {
47            ((GridLayoutManager) layoutManager).setSpanCount(columnInfo.count);
48        }
49    }
50
51    private static ColumnInfo calculateColumnCount(Context context, int availableWidth, @DimenRes int desiredSize) {
52        final float desiredWidth = context.getResources().getDimension(desiredSize);
53        final int columns = Math.round(availableWidth / desiredWidth);
54        final int realWidth = availableWidth / columns;
55        Log.d(Config.LOGTAG, "desired=" + desiredWidth + " real=" + realWidth);
56        return new ColumnInfo(columns, realWidth);
57    }
58
59    public static int getCurrentColumnCount(RecyclerView recyclerView) {
60        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
61        if (layoutManager instanceof GridLayoutManager) {
62            return ((GridLayoutManager) layoutManager).getSpanCount();
63        } else {
64            return 0;
65        }
66    }
67
68    public static class ColumnInfo {
69        private final int count;
70        private final int width;
71
72        private ColumnInfo(int count, int width) {
73            this.count = count;
74            this.width = width;
75        }
76    }
77
78}