Add tests for list preloader

1 files changed, 221 insertions, 0 deletions

diff --git a/library/tests/src/com/bumptech/glide/ListPreloaderTest.java b/library/tests/src/com/bumptech/glide/ListPreloaderTest.java
new file mode 100644
index 00000000..3ae90507
--- /dev/null
+++ b/library/tests/src/com/bumptech/glide/ListPreloaderTest.java
@@ -0,0 +1,221 @@
+package com.bumptech.glide;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.test.AndroidTestCase;
+import com.bumptech.glide.loader.model.ModelLoader;
+import com.bumptech.glide.loader.stream.StreamLoader;
+import com.bumptech.glide.util.Log;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class ListPreloaderTest extends AndroidTestCase {
+
+    static {
+        Log.DEBUG = true;
+    }
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+    }
+
+    public void testGetItemsIsCalledIncreasing() {
+        final AtomicBoolean called = new AtomicBoolean(false);
+        ListPreloaderAdapter preloader = new ListPreloaderAdapter(getContext(), 10) {
+            @Override
+            protected List<Object> getItems(int start, int end) {
+                called.set(true);
+                assertEquals(11, start);
+                assertEquals(21, end);
+                return super.getItems(start, end);
+            }
+        };
+        preloader.onScroll(null, 1, 10, 30);
+        assertTrue(called.get());
+    }
+
+    public void testGetItemsIsCalledDecreasing() {
+        final AtomicBoolean called = new AtomicBoolean(false);
+        ListPreloaderAdapter preloader = new ListPreloaderAdapter(getContext(), 10) {
+            @Override
+            protected List<Object> getItems(int start, int end) {
+                // Ignore the preload caused from us starting at the end
+                if (start == 30) {
+                    return Collections.EMPTY_LIST;
+                }
+                called.set(true);
+                assertEquals(19, start);
+                assertEquals(29, end);
+                return super.getItems(start, end);
+            }
+        };
+        preloader.onScroll(null, 30, 10, 30);
+        preloader.onScroll(null, 29, 10, 30);
+        assertTrue(called.get());
+    }
+
+    public void testGetItemsIsNeverCalledWithEndGreaterThanTotalItems() {
+        final AtomicBoolean called = new AtomicBoolean(false);
+        ListPreloaderAdapter preloader = new ListPreloaderAdapter(getContext(), 10) {
+            @Override
+            protected List<Object> getItems(int start, int end) {
+                called.set(true);
+                assertEquals(26, start);
+                assertEquals(30, end);
+                return super.getItems(start, end);
+            }
+        };
+        preloader.onScroll(null, 16, 10, 30);
+        assertTrue(called.get());
+    }
+
+    public void testGetItemsIsNeverCalledWithStartLessThanZero() {
+        final AtomicBoolean called = new AtomicBoolean(false);
+        ListPreloaderAdapter preloader = new ListPreloaderAdapter(getContext(), 10) {
+            @Override
+            protected List<Object> getItems(int start, int end) {
+                if (start == 17) {
+                    return Collections.EMPTY_LIST;
+                }
+                called.set(true);
+                assertEquals(0, start);
+                assertEquals(6, end);
+                return super.getItems(start, end);
+            }
+        };
+        preloader.onScroll(null, 7, 10, 30);
+        preloader.onScroll(null, 6, 10, 30);
+        assertTrue(called.get());
+    }
+
+    public void testDontPreloadItemsRepeatedlyWhileIncreasing() {
+        final AtomicInteger called = new AtomicInteger();
+        ListPreloaderAdapter preloader = new ListPreloaderAdapter(getContext(), 10) {
+            @Override
+            protected List<Object> getItems(int start, int end) {
+                final int current = called.getAndIncrement();
+                if (current == 0) {
+                    assertEquals(11, start);
+                    assertEquals(21, end);
+                } else if (current == 1) {
+                    assertEquals(21, start);
+                    assertEquals(24, end);
+                }
+                return super.getItems(start, end);
+            }
+        };
+
+        preloader.onScroll(null, 1, 10, 30);
+        preloader.onScroll(null, 4, 10, 30);
+
+        assertEquals(2, called.get());
+    }
+
+    public void testDontPreloadItemsRepeatedlyWhileDecreasing() {
+        final AtomicInteger called = new AtomicInteger();
+        ListPreloaderAdapter preloader = new ListPreloaderAdapter(getContext(), 10) {
+            @Override
+            protected List<Object> getItems(int start, int end) {
+                if (start == 30) {
+                    return Collections.EMPTY_LIST;
+                }
+                final int current = called.getAndIncrement();
+                if (current == 0) {
+                    assertEquals(10, start);
+                    assertEquals(20, end);
+                } else if (current == 1) {
+                    assertEquals(7, start);
+                    assertEquals(10, end);
+                }
+                return super.getItems(start, end);
+            }
+        };
+
+        preloader.onScroll(null, 21, 10, 30);
+        preloader.onScroll(null, 20, 10, 30);
+        preloader.onScroll(null, 17, 10, 30);
+        assertEquals(2, called.get());
+    }
+
+    public void testItemsArePreloadedWithGlide() {
+        final List<Object> objects = new ArrayList<Object>();
+        objects.add(new Object());
+        objects.add(new Object());
+        final HashSet<Object> loadedObjects = new HashSet<Object>();
+        ListPreloaderAdapter preloader = new ListPreloaderAdapter(getContext(), 10) {
+            @Override
+            protected List<Object> getItems(int start, int end) {
+                return objects;
+            }
+
+            @Override
+            protected Glide.Request<Object> getRequest(Object item) {
+                loadedObjects.add(item);
+                return super.getRequest(item);
+            }
+        };
+
+        preloader.onScroll(null, 1, 10, 30);
+
+        assertEquals(objects.size(), loadedObjects.size());
+        for (Object object : objects) {
+            assertTrue(loadedObjects.contains(object));
+        }
+    }
+
+    private static class ListPreloaderAdapter extends ListPreloader<Object> {
+        public Bitmap bitmap = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
+
+        public ListPreloaderAdapter(Context context, int maxPreload) {
+            super(context, maxPreload);
+        }
+
+        @Override
+        protected int[] getDimensions(Object item) {
+            return new int[] { 100, 100 };
+        }
+
+        @Override
+        protected List<Object> getItems(int start, int end) {
+            ArrayList<Object> result = new ArrayList<Object>(end - start);
+            Collections.fill(result, new Object());
+            return result;
+        }
+
+        @Override
+        protected Glide.Request<Object> getRequest(Object item) {
+            return Glide.using(new ModelLoader<Object>() {
+                @Override
+                public StreamLoader getStreamLoader(Object model, int width, int height) {
+                    return new StreamLoader() {
+                        @Override
+                        public void loadStream(StreamReadyCallback cb) {
+                            ByteArrayOutputStream os = new ByteArrayOutputStream();
+                            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
+                            ByteArrayInputStream is = new ByteArrayInputStream(os.toByteArray());
+                            cb.onStreamReady(is);
+
+                        }
+
+                        @Override
+                        public void cancel() {
+                        }
+                    };
+                }
+
+                @Override
+                public String getId(Object model) {
+                    return String.valueOf(model.hashCode());
+                }
+            }).load(item);
+        }
+    }
+}