Add Image resizeMode repeat on iOS

Summary:
This adds a new resize mode for iOS 'repeat' that tiles the image over it's frame. This allow to easily create a view with a repeating background pattern which there is no way to do at the moment without including a bunch of different sized assets.

I'm not 100% sure it should be a resizeMode or a separate prop but I went with resizeMode since it made more sense to me and the are not really any use cases where we'd want to use this with another resizeMode other than 'stretch'.

**Test plan**

Tested mainly by adding a UIExplorer example, also tested that changing the resizeMode prop from and to 'repeat' worked properly.
![screen shot 2016-06-07 at 3 06 17 am](https://cloud.githubusercontent.com/assets/2677334/15848755/d95d8046-2c5c-11e6-9f3d-1ce8a1c9c846.png)

I'd like to implement this on Android too but it is a bit trickier since Fresco's ImageView doesn't support image tiling and would require submitting a PR there too :(
Closes facebook#7968

Differential Revision: D3469119

Pulled By: javache

fbshipit-source-id: ab9dbfe448a5b0771dbf0c41fcceeb366210f583

Examples/UIExplorer/ImageExample.js

@@ -505,6 +505,18 @@ exports.examples = [
                     source={image}
                   />
                 </View>
+                { Platform.OS === 'ios' ?
+                  <View style={styles.leftMargin}>
+                    <Text style={[styles.resizeModeText]}>
+                      Repeat
+                    </Text>
+                    <Image
+                      style={styles.resizeMode}
+                      resizeMode={Image.resizeMode.repeat}
+                      source={image}
+                    />
+                  </View>
+                : null }
                 { Platform.OS === 'android' ?
                   <View style={styles.leftMargin}>
                     <Text style={[styles.resizeModeText]}>

Libraries/Image/Image.ios.js

@@ -127,8 +127,11 @@ const Image = React.createClass({
      *
      * 'stretch': Scale width and height independently, This may change the
      * aspect ratio of the src.
+     *
+     * 'repeat': Repeat the image to cover the frame of the view. The
+     * image will keep it's size and aspect ratio. (iOS only)
      */
-    resizeMode: PropTypes.oneOf(['cover', 'contain', 'stretch']),
+    resizeMode: PropTypes.oneOf(['cover', 'contain', 'stretch', 'repeat']),
     /**
      * A unique identifier for this element to be used in UI Automation
      * testing scripts.

Libraries/Image/ImageResizeMode.js

@@ -40,6 +40,12 @@ var ImageResizeMode = keyMirror({
   * The image will not be scaled up.
   */
   center: null,
+
+  /**
+   * repeat - The image will be repeated to cover the frame of the View. The
+   * image will keep it's size and aspect ratio.
+   */
+  repeat: null,
 });
 
 module.exports = ImageResizeMode;

Libraries/Image/RCTImageUtils.m

@@ -64,6 +64,7 @@ CGRect RCTTargetRect(CGSize sourceSize, CGSize destSize,
 
   switch (resizeMode) {
     case RCTResizeModeStretch:
+    case RCTResizeModeRepeat:
 
       return (CGRect){CGPointZero, RCTCeilSize(destSize, destScale)};
 
@@ -204,6 +205,10 @@ BOOL RCTUpscalingRequired(CGSize sourceSize, CGFloat sourceScale,
 
         return destSize.width > sourceSize.width;
       }
+
+    case RCTResizeModeRepeat:
+
+      return NO;
   }
 }
 

Libraries/Image/RCTImageView.h

@@ -22,5 +22,6 @@
 @property (nonatomic, assign) UIImageRenderingMode renderingMode;
 @property (nonatomic, strong) RCTImageSource *source;
 @property (nonatomic, assign) CGFloat blurRadius;
+@property (nonatomic, assign) RCTResizeMode resizeMode;
 
 @end

Libraries/Image/RCTImageView.m

@@ -95,11 +95,12 @@ - (void)updateImage
     image = [image imageWithRenderingMode:_renderingMode];
   }
 
-  // Applying capInsets of 0 will switch the "resizingMode" of the image to "tile" which is undesired
-  if (!UIEdgeInsetsEqualToEdgeInsets(UIEdgeInsetsZero, _capInsets)) {
+  if (_resizeMode == RCTResizeModeRepeat) {
+    image = [image resizableImageWithCapInsets:_capInsets resizingMode:UIImageResizingModeTile];
+  } else if (!UIEdgeInsetsEqualToEdgeInsets(UIEdgeInsetsZero, _capInsets)) {
+    // Applying capInsets of 0 will switch the "resizingMode" of the image to "tile" which is undesired
     image = [image resizableImageWithCapInsets:_capInsets resizingMode:UIImageResizingModeStretch];
   }
-
   // Apply trilinear filtering to smooth out mis-sized images
   self.layer.minificationFilter = kCAFilterTrilinear;
   self.layer.magnificationFilter = kCAFilterTrilinear;
@@ -161,10 +162,19 @@ - (BOOL)sourceNeedsReload
   return UIEdgeInsetsEqualToEdgeInsets(_capInsets, UIEdgeInsetsZero);
 }
 
-- (void)setContentMode:(UIViewContentMode)contentMode
+- (void)setResizeMode:(RCTResizeMode)resizeMode
 {
-  if (self.contentMode != contentMode) {
-    super.contentMode = contentMode;
+  if (_resizeMode != resizeMode) {
+    _resizeMode = resizeMode;
+
+    if (_resizeMode == RCTResizeModeRepeat) {
+      // Repeat resize mode is handled by the UIImage. Use scale to fill
+      // so the repeated image fills the UIImageView.
+      self.contentMode = UIViewContentModeScaleToFill;
+    } else {
+      self.contentMode = (UIViewContentMode)resizeMode;
+    }
+
     if ([self sourceNeedsReload]) {
       [self reloadImage];
     }
@@ -230,7 +240,7 @@ - (void)reloadImage
                                             size:imageSize
                                            scale:imageScale
                                          clipped:NO
-                                      resizeMode:(RCTResizeMode)self.contentMode
+                                      resizeMode:_resizeMode
                                    progressBlock:progressHandler
                                  completionBlock:^(NSError *error, UIImage *loadedImage) {
       RCTImageView *strongSelf = weakSelf;

Libraries/Image/RCTImageViewManager.m

@@ -33,7 +33,7 @@ - (UIView *)view
 RCT_EXPORT_VIEW_PROPERTY(onError, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(onLoad, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(onLoadEnd, RCTDirectEventBlock)
-RCT_REMAP_VIEW_PROPERTY(resizeMode, contentMode, RCTResizeMode)
+RCT_EXPORT_VIEW_PROPERTY(resizeMode, RCTResizeMode)
 RCT_EXPORT_VIEW_PROPERTY(source, RCTImageSource)
 RCT_CUSTOM_VIEW_PROPERTY(tintColor, UIColor, RCTImageView)
 {

Libraries/Image/RCTResizeMode.h

@@ -13,6 +13,7 @@ typedef NS_ENUM(NSInteger, RCTResizeMode) {
   RCTResizeModeCover = UIViewContentModeScaleAspectFill,
   RCTResizeModeContain = UIViewContentModeScaleAspectFit,
   RCTResizeModeStretch = UIViewContentModeScaleToFill,
+  RCTResizeModeRepeat = -1, // Use negative values to avoid conflicts with iOS enum values.
 };
 
 @interface RCTConvert(RCTResizeMode)

Libraries/Image/RCTResizeMode.m

@@ -15,6 +15,7 @@ @implementation RCTConvert(RCTResizeMode)
   @"cover": @(RCTResizeModeCover),
   @"contain": @(RCTResizeModeContain),
   @"stretch": @(RCTResizeModeStretch),
+  @"repeat": @(RCTResizeModeRepeat),
 }), RCTResizeModeStretch, integerValue)
 
 @end