Merge pull request #6149 from SimonBrandner/fix/jumps-image-view

src/components/views/elements/ImageView.tsx

@@ -95,8 +95,6 @@ export default class ImageView extends React.Component<IProps, IState> {
 
     private initX = 0;
     private initY = 0;
-    private lastX = 0;
-    private lastY = 0;
     private previousX = 0;
     private previousY = 0;
 
@@ -105,23 +103,35 @@ export default class ImageView extends React.Component<IProps, IState> {
         // needs to be passive in order to work with Chromium
         this.focusLock.current.addEventListener('wheel', this.onWheel, { passive: false });
         // We want to recalculate zoom whenever the window's size changes
-        window.addEventListener("resize", this.calculateZoom);
+        window.addEventListener("resize", this.recalculateZoom);
         // After the image loads for the first time we want to calculate the zoom
-        this.image.current.addEventListener("load", this.calculateZoom);
+        this.image.current.addEventListener("load", this.recalculateZoom);
     }
 
     componentWillUnmount() {
         this.focusLock.current.removeEventListener('wheel', this.onWheel);
-        window.removeEventListener("resize", this.calculateZoom);
-        this.image.current.removeEventListener("load", this.calculateZoom);
+        window.removeEventListener("resize", this.recalculateZoom);
+        this.image.current.removeEventListener("load", this.recalculateZoom);
     }
 
-    private calculateZoom = () => {
+    private recalculateZoom = () => {
+        this.setZoomAndRotation();
+    }
+
+    private setZoomAndRotation = (inputRotation?: number) => {
         const image = this.image.current;
         const imageWrapper = this.imageWrapper.current;
 
-        const zoomX = imageWrapper.clientWidth / image.naturalWidth;
-        const zoomY = imageWrapper.clientHeight / image.naturalHeight;
+        const rotation = inputRotation || this.state.rotation;
+
+        const imageIsNotFlipped = rotation % 180 === 0;
+
+        // If the image is rotated take it into account
+        const width = imageIsNotFlipped ? image.naturalWidth : image.naturalHeight;
+        const height = imageIsNotFlipped ? image.naturalHeight : image.naturalWidth;
+
+        const zoomX = imageWrapper.clientWidth / width;
+        const zoomY = imageWrapper.clientHeight / height;
 
         // If the image is smaller in both dimensions set its the zoom to 1 to
         // display it in its original size
@@ -130,6 +140,7 @@ export default class ImageView extends React.Component<IProps, IState> {
                 zoom: 1,
                 minZoom: 1,
                 maxZoom: 1,
+                rotation: rotation,
             });
             return;
         }
@@ -138,10 +149,14 @@ export default class ImageView extends React.Component<IProps, IState> {
         // image by default
         const minZoom = Math.min(zoomX, zoomY) * MAX_SCALE;
 
-        if (this.state.zoom <= this.state.minZoom) this.setState({zoom: minZoom});
+        // If zoom is smaller than minZoom don't go below that value
+        const zoom = (this.state.zoom <= this.state.minZoom) ? minZoom : this.state.zoom;
+
         this.setState({
             minZoom: minZoom,
             maxZoom: 1,
+            rotation: rotation,
+            zoom: zoom,
         });
     }
 
@@ -192,14 +207,12 @@ export default class ImageView extends React.Component<IProps, IState> {
 
     private onRotateCounterClockwiseClick = () => {
         const cur = this.state.rotation;
-        const rotationDegrees = cur - 90;
-        this.setState({ rotation: rotationDegrees });
+        this.setZoomAndRotation(cur - 90);
     };
 
     private onRotateClockwiseClick = () => {
         const cur = this.state.rotation;
-        const rotationDegrees = cur + 90;
-        this.setState({ rotation: rotationDegrees });
+        this.setZoomAndRotation(cur + 90);
     };
 
     private onDownloadClick = () => {
@@ -253,8 +266,8 @@ export default class ImageView extends React.Component<IProps, IState> {
         this.setState({ moving: true });
         this.previousX = this.state.translationX;
         this.previousY = this.state.translationY;
-        this.initX = ev.pageX - this.lastX;
-        this.initY = ev.pageY - this.lastY;
+        this.initX = ev.pageX - this.state.translationX;
+        this.initY = ev.pageY - this.state.translationY;
     };
 
     private onMoving = (ev: React.MouseEvent) => {
@@ -263,11 +276,9 @@ export default class ImageView extends React.Component<IProps, IState> {
 
         if (!this.state.moving) return;
 
-        this.lastX = ev.pageX - this.initX;
-        this.lastY = ev.pageY - this.initY;
         this.setState({
-            translationX: this.lastX,
-            translationY: this.lastY,
+            translationX: ev.pageX - this.initX,
+            translationY: ev.pageY - this.initY,
         });
     };
 
@@ -283,6 +294,8 @@ export default class ImageView extends React.Component<IProps, IState> {
                 translationX: 0,
                 translationY: 0,
             });
+            this.initX = 0;
+            this.initY = 0;
         }
         this.setState({ moving: false });
     };