Fix gallery image dimensions (#9247)

app/screens/gallery/index.tsx

@@ -2,8 +2,8 @@
 // See LICENSE.txt for license information.
 
 import RNUtils from '@mattermost/rnutils';
-import React, {useCallback, useEffect, useMemo, useRef, useState} from 'react';
+import React, {useCallback, useEffect, useRef, useState} from 'react';
-import {DeviceEventEmitter, Platform, StyleSheet, View} from 'react-native';
+import {DeviceEventEmitter, Platform, View} from 'react-native';
 
 import {Events} from '@constants';
 import useAndroidHardwareBackHandler from '@hooks/android_back_handler';
@@ -28,12 +28,6 @@ type Props = {
     items: GalleryItemType[];
 }
 
-const styles = StyleSheet.create({
-    container: {
-        flex: 1,
-    },
-});
-
 const GalleryScreen = ({componentId, galleryIdentifier, hideActions, initialIndex, items}: Props) => {
     const dim = useWindowDimensions();
     const isTablet = useIsTablet();
@@ -41,13 +35,7 @@ const GalleryScreen = ({componentId, galleryIdentifier, hideActions, initialInde
     const {headerAndFooterHidden, hideHeaderAndFooter, headerStyles, footerStyles} = useGalleryControls();
     const galleryRef = useRef<GalleryRef>(null);
 
-    const containerStyle = useMemo(() => {
+    const containerStyle = dim;
-        if (Platform.OS === 'ios') {
-            return dim;
-        }
-
-        return styles.container;
-    }, [dim]);
 
     const onClose = useCallback(() => {
         // We keep the un freeze here as we want
@@ -81,6 +69,10 @@ const GalleryScreen = ({componentId, galleryIdentifier, hideActions, initialInde
             onClose();
         });
 
+        if (Platform.OS === 'android' && Platform.Version >= 34) {
+            RNUtils.setNavigationBarColor('black', true);
+        }
+
         return () => {
             listener.remove();
         };

app/screens/gallery/lightbox_swipeout/lightbox.tsx

@@ -1,19 +1,14 @@
 // Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
 // See LICENSE.txt for license information.
 
-// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
-// See LICENSE.txt for license information.
-
 import {Image, type ImageSource} from 'expo-image';
 import React, {useEffect, useMemo, useState} from 'react';
-import {type ImageStyle, Platform, StyleSheet, View, type ViewStyle} from 'react-native';
+import {type ImageStyle, StyleSheet, View, type ViewStyle} from 'react-native';
 import Animated, {
     interpolate, runOnJS, runOnUI,
     useAnimatedStyle, withTiming,
 } from 'react-native-reanimated';
-import {useSafeAreaInsets} from 'react-native-safe-area-context';
 
-import {useDefaultHeaderHeight} from '@hooks/header';
 import {calculateDimensions} from '@utils/images';
 
 import {pagerTimingConfig} from '../animation_config/timing';
@@ -66,9 +61,6 @@ export default function Lightbox({
     } = useLightboxSharedValues();
     const [renderChildren, setRenderChildren] = useState<boolean>(false);
     const childLayoutTimeoutRef = React.useRef<NodeJS.Timeout>();
-    const insets = useSafeAreaInsets();
-    const headerHeight = useDefaultHeaderHeight() - insets.top;
-    const targetHeightDiff = Platform.OS === 'ios' ? 0 : (headerHeight / 2);
 
     const animateOnMount = () => {
         'worklet';
@@ -94,6 +86,9 @@ export default function Lightbox({
                 childLayoutTimeoutRef.current = undefined;
             }
         };
+
+    // no need to add animateOnMount as this function uses references and is only needed on mount
+    // eslint-disable-next-line react-hooks/exhaustive-deps
     }, []);
 
     const {width: tw, height: th} = useMemo(() => calculateDimensions(
@@ -139,7 +134,7 @@ export default function Lightbox({
             interpolate(animationProgress.value, [0, 1], range);
 
         const targetX = (targetDimensions.width - tw) / 2;
-        const targetY = ((targetDimensions.height - th) / 2) - targetHeightDiff;
+        const targetY = ((targetDimensions.height - th) / 2);
 
         const top =
             translateY.value +

app/utils/images/index.test.ts

@@ -197,6 +197,46 @@ describe('calculateDimensions', () => {
         expect(result.width).toBe(300);
         expect(result.height).toBe(300);
     });
+
+    it('should constrain portrait image width when scaling to viewport height would cause overflow', () => {
+        // Portrait image 380×800, viewport 400×900
+        // Without fix: height=900, width=900×(380/800)=427.5 (OVERFLOW!)
+        // With fix: should scale based on width instead
+        const result = calculateDimensions(800, 380, 400, 900, true);
+        expect(result.width).toBeLessThanOrEqual(400);
+        expect(result.height).toBeLessThanOrEqual(900);
+
+        // Should constrain to width: 400w, height=400×(800/380)≈842
+        expect(result.width).toBe(400);
+        expect(result.height).toBeCloseTo(842.1, 0);
+    });
+
+    it('should constrain landscape image height when scaling to viewport width would cause overflow', () => {
+        // Landscape image 800×380, viewport 900×400
+        // Without fix: width=900, height=900×(380/800)=427.5 (OVERFLOW!)
+        // With fix: should scale based on height instead
+        const result = calculateDimensions(380, 800, 900, 400, true);
+        expect(result.width).toBeLessThanOrEqual(900);
+        expect(result.height).toBeLessThanOrEqual(400);
+
+        // Should constrain to height: 400h, width=400×(800/380)≈842
+        expect(result.height).toBe(400);
+        expect(result.width).toBeCloseTo(842.1, 0);
+    });
+
+    it('should handle extreme portrait aspect ratio with matchViewPort', () => {
+        // Very tall portrait image 200×1000 (1:5 ratio), viewport 300×600
+        // Would try to fit to height: 600h, width=600×(200/1000)=120 (OK)
+        // But if viewport is narrower: 100×600
+        // Would try: 600h, width=600×(200/1000)=120 (OVERFLOW!)
+        const result = calculateDimensions(1000, 200, 100, 600, true);
+        expect(result.width).toBeLessThanOrEqual(100);
+        expect(result.height).toBeLessThanOrEqual(600);
+
+        // Should constrain to width: 100w, height=100×(1000/200)=500
+        expect(result.width).toBe(100);
+        expect(result.height).toBe(500);
+    });
 });
 
 describe('getViewPortWidth', () => {

app/utils/images/index.ts

@@ -57,10 +57,22 @@ export const calculateDimensions = (height?: number, width?: number, viewPortWid
             // Portrait: fit to viewport height
             imageHeight = viewPortHeight;
             imageWidth = imageHeight * heightRatio;
+
+            // Ensure width doesn't exceed viewport
+            if (imageWidth > viewPortWidth) {
+                imageWidth = viewPortWidth;
+                imageHeight = imageWidth * ratio;
+            }
         } else {
             // Landscape or square: fit to viewport width
             imageWidth = viewPortWidth;
             imageHeight = imageWidth * ratio;
+
+            // Ensure height doesn't exceed viewport
+            if (imageHeight > viewPortHeight) {
+                imageHeight = viewPortHeight;
+                imageWidth = imageHeight * heightRatio;
+            }
         }
     }