Panorama (#4467)

* panoramic images fixed

* made requested changes

* Minor refactoring

Co-authored-by: Aditya Srivastava <iamaditya2009@gmail.com>

data-client/src/main/java/org/wikipedia/gallery/ImageInfo.java

@@ -29,6 +29,16 @@ public class ImageInfo implements Serializable {
     @Nullable private String user;
     @Nullable private String timestamp;
 
+    /**
+     * Query width, default width parameter of the API query in pixels.
+     */
+    final private static int QUERY_WIDTH = 640;
+
+    /**
+     * Threshold height, the minimum height of the image in pixels.
+     */
+    final private static int THRESHOLD_HEIGHT = 220;
+
     @NonNull
     public String getSource() {
         return StringUtils.defaultString(source);
@@ -50,11 +60,24 @@ public class ImageInfo implements Serializable {
         return height;
     }
 
+    /**
+     * Get the thumbnail width.
+     * @return
+     */
+    public int getThumbWidth() { return thumbWidth; }
+
+    /**
+     * Get the thumbnail height.
+     * @return
+     */
+    public int getThumbHeight() { return thumbHeight; }
+
     @NonNull public String getMimeType() {
         return StringUtils.defaultString(mimeType, "*/*");
     }
 
     @NonNull public String getThumbUrl() {
+        updateThumbUrl();
         return StringUtils.defaultString(thumbUrl);
     }
 
@@ -73,4 +96,26 @@ public class ImageInfo implements Serializable {
     @Nullable public ExtMetadata getMetadata() {
         return metadata;
     }
+
+    /**
+     * Updates the ThumbUrl if image dimensions are not sufficient.
+     * Specifically, in panoramic images the height retrieved is less than required due to large width to height ratio,
+     * so we update the thumb url keeping a minimum height threshold.
+     */
+    private void updateThumbUrl() {
+        // If thumbHeight retrieved from API is less than THRESHOLD_HEIGHT
+        if(getThumbHeight() < THRESHOLD_HEIGHT){
+            // If thumbWidthRetrieved is same as queried width ( If not tells us that the image has no larger dimensions. )
+            if(getThumbWidth() == QUERY_WIDTH){
+                // Calculate new width depending on the aspect ratio.
+                final int finalWidth = (int)(THRESHOLD_HEIGHT * getThumbWidth() * 1.0 / getThumbHeight());
+                thumbHeight = THRESHOLD_HEIGHT;
+                thumbWidth = finalWidth;
+                final String toReplace = "/" + QUERY_WIDTH + "px";
+                final int position = thumbUrl.lastIndexOf(toReplace);
+                thumbUrl = (new StringBuilder(thumbUrl)).replace(position, position + toReplace.length(), "/" + thumbWidth + "px").toString();
+            }
+        }
+    }
+
 }