Patch to chrisbanes/PhotoView for issue #444

patch.diff

From 7ab87c7543deebb48a8c1ab482eb7cab524f2d29 Mon Sep 17 00:00:00 2001
From: Julian <julian@julians-mbp.attlocal.net>
Date: Thu, 17 Nov 2016 13:34:11 -0800
Subject: [PATCH] destroying the mid zoom

---
 .../co/senab/photoview/DefaultOnDoubleTapListener.java  | 17 ++++++++++++-----
 .../java/uk/co/senab/photoview/PhotoViewAttacher.java   | 16 +++++++++++-----
 2 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/app/src/main/java/uk/co/senab/photoview/DefaultOnDoubleTapListener.java b/app/src/main/java/uk/co/senab/photoview/DefaultOnDoubleTapListener.java
index b5a8f21..c0b2b25 100755
--- a/app/src/main/java/uk/co/senab/photoview/DefaultOnDoubleTapListener.java
+++ b/app/src/main/java/uk/co/senab/photoview/DefaultOnDoubleTapListener.java
@@ -77,13 +77,20 @@ public class DefaultOnDoubleTapListener implements GestureDetector.OnDoubleTapLi
             float x = ev.getX();
             float y = ev.getY();
 
-            if (scale < photoViewAttacher.getMediumScale()) {
-                photoViewAttacher.setScale(photoViewAttacher.getMediumScale(), x, y, true);
-            } else if (scale >= photoViewAttacher.getMediumScale() && scale < photoViewAttacher.getMaximumScale()) {
-                photoViewAttacher.setScale(photoViewAttacher.getMaximumScale(), x, y, true);
+            float nextScale;
+            if (photoViewAttacher.getMediumScale() >= 0) {
+                if (scale < photoViewAttacher.getMediumScale())
+                    nextScale = photoViewAttacher.getMediumScale();
+                else if (scale >= photoViewAttacher.getMediumScale() && scale < photoViewAttacher.getMaximumScale())
+                    nextScale = photoViewAttacher.getMaximumScale();
+                else
+                    nextScale = photoViewAttacher.getMinimumScale();
             } else {
-                photoViewAttacher.setScale(photoViewAttacher.getMinimumScale(), x, y, true);
+                nextScale = (scale == photoViewAttacher.getMaximumScale() ?
+                        photoViewAttacher.getMinimumScale() : photoViewAttacher.getMaximumScale());
             }
+
+            photoViewAttacher.setScale(nextScale, x, y, true);
         } catch (ArrayIndexOutOfBoundsException e) {
             // Can sometimes happen when getX() and getY() is called
         }
diff --git a/app/src/main/java/uk/co/senab/photoview/PhotoViewAttacher.java b/app/src/main/java/uk/co/senab/photoview/PhotoViewAttacher.java
index 8bb34e9..65db4b0 100755
--- a/app/src/main/java/uk/co/senab/photoview/PhotoViewAttacher.java
+++ b/app/src/main/java/uk/co/senab/photoview/PhotoViewAttacher.java
@@ -76,12 +76,18 @@ public class PhotoViewAttacher implements IPhotoView, View.OnTouchListener,
 
     private static void checkZoomLevels(float minZoom, float midZoom,
                                         float maxZoom) {
-        if (minZoom >= midZoom) {
+        if (minZoom >= maxZoom) {
             throw new IllegalArgumentException(
-                    "Minimum zoom has to be less than Medium zoom. Call setMinimumZoom() with a more appropriate value");
-        } else if (midZoom >= maxZoom) {
-            throw new IllegalArgumentException(
-                    "Medium zoom has to be less than Maximum zoom. Call setMaximumZoom() with a more appropriate value");
+                    "Minimum zoom has to be less than Maximum zoom. Call setMinimumZoom() with a more appropriate value");
+        }
+        if (midZoom >= 0) {
+            if (minZoom >= midZoom) {
+                throw new IllegalArgumentException(
+                        "Minimum zoom has to be less than Medium zoom. Call setMinimumZoom() with a more appropriate value");
+            } else if (midZoom >= maxZoom) {
+                throw new IllegalArgumentException(
+                        "Medium zoom has to be less than Maximum zoom. Call setMaximumZoom() with a more appropriate value");
+            }
         }
     }
 
-- 
2.6.2