Add pinch-to-zoom in video message capture

submodules/LegacyComponents/Sources/TGVideoCameraPipeline.h

@@ -15,6 +15,9 @@
 
 @property (nonatomic, copy) void (^micLevel)(CGFloat);
 
+@property (nonatomic, readonly) bool isZoomAvailable;
+@property (nonatomic, assign) CGFloat zoomLevel;
+
 - (instancetype)initWithDelegate:(id<TGVideoCameraPipelineDelegate>)delegate position:(AVCaptureDevicePosition)position callbackQueue:(dispatch_queue_t)queue liveUploadInterface:(id<TGLiveUploadInterface>)liveUploadInterface;
 
 - (void)startRunning;

submodules/LegacyComponents/Sources/TGVideoCameraPipeline.m

@@ -864,6 +864,52 @@ static CGFloat angleOffsetFromPortraitOrientationToOrientation(AVCaptureVideoOri
     return _recorder.videoDuration;
 }
 
+- (CGFloat)zoomLevel
+{
+    if (![_videoDevice respondsToSelector:@selector(videoZoomFactor)])
+        return 1.0f;
+    
+    return (_videoDevice.videoZoomFactor - 1.0f) / ([self _maximumZoomFactor] - 1.0f);
+}
+
+- (CGFloat)_maximumZoomFactor
+{
+    return MIN(5.0f, _videoDevice.activeFormat.videoMaxZoomFactor);
+}
+
+- (void)setZoomLevel:(CGFloat)zoomLevel
+{
+    zoomLevel = MAX(0.0f, MIN(1.0f, zoomLevel));
+    
+    __weak TGVideoCameraPipeline *weakSelf = self;
+    [[TGVideoCameraPipeline cameraQueue] dispatch:^
+    {
+        __strong TGVideoCameraPipeline *strongSelf = weakSelf;
+        if (strongSelf == nil)
+            return;
+        
+        [self _reconfigureDevice:_videoDevice withBlock:^(AVCaptureDevice *device) {
+            device.videoZoomFactor = MAX(1.0f, MIN([strongSelf _maximumZoomFactor], 1.0f + ([strongSelf _maximumZoomFactor] - 1.0f) * zoomLevel));
+        }];
+    }];
+}
+
+- (bool)isZoomAvailable
+{
+    return [TGVideoCameraPipeline _isZoomAvailableForDevice:_videoDevice];
+}
+
++ (bool)_isZoomAvailableForDevice:(AVCaptureDevice *)device
+{
+    if (![device respondsToSelector:@selector(setVideoZoomFactor:)])
+        return false;
+    
+    if (device.position == AVCaptureDevicePositionFront)
+        return false;
+    
+    return true;
+}
+
 - (void)setCameraPosition:(AVCaptureDevicePosition)position
 {
     @synchronized (self)

submodules/LegacyComponents/Sources/TGVideoMessageCaptureController.m

@@ -91,6 +91,8 @@ typedef enum
     TGVideoCameraGLView *_previewView;
     TGVideoMessageRingView *_ringView;
     
+    UIPinchGestureRecognizer *_pinchGestureRecognizer;
+    
     UIView *_separatorView;
     
     UIImageView *_placeholderView;
@@ -344,7 +346,6 @@ typedef enum
     [_circleWrapperView addSubview:_ringView];
     
     CGRect controlsFrame = _controlsFrame;
-//    controlsFrame.size.width = _wrapperView.frame.size.width;
     
     _controlsView = [[TGVideoMessageControls alloc] initWithFrame:controlsFrame assets:_assets slowmodeTimestamp:_slowmodeTimestamp slowmodeView:_slowmodeView];
     _controlsView.pallete = self.pallete;
@@ -417,12 +418,43 @@ typedef enum
         [self.view addSubview:_switchButton];
     }
     
+    _pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinch:)];
+    _pinchGestureRecognizer.delegate = self;
+    [self.view addGestureRecognizer:_pinchGestureRecognizer];
+    
     void (^voidBlock)(void) = ^{};
     _buttonHandler = [[PGCameraVolumeButtonHandler alloc] initWithUpButtonPressedBlock:voidBlock upButtonReleasedBlock:voidBlock downButtonPressedBlock:voidBlock downButtonReleasedBlock:voidBlock];
     
     [self configureCamera];
 }
 
+- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
+{
+    if (gestureRecognizer == _pinchGestureRecognizer)
+        return _capturePipeline.isZoomAvailable;
+    
+    return true;
+}
+
+- (void)handlePinch:(UIPinchGestureRecognizer *)gestureRecognizer
+{
+    switch (gestureRecognizer.state)
+    {
+        case UIGestureRecognizerStateChanged:
+        {
+            CGFloat delta = (gestureRecognizer.scale - 1.0f) / 1.5f;
+            CGFloat value = MAX(0.0f, MIN(1.0f, _capturePipeline.zoomLevel + delta));
+            
+            [_capturePipeline setZoomLevel:value];
+            
+            gestureRecognizer.scale = 1.0f;
+        }
+            break;
+        default:
+            break;
+    }
+}
+
 - (TGVideoMessageTransitionType)_transitionType
 {
     static dispatch_once_t onceToken;