diff --git a/JASidePanels/Source/JASidePanelController.h b/JASidePanels/Source/JASidePanelController.h
index f806809..0ec0fd5 100644
--- a/JASidePanels/Source/JASidePanelController.h
+++ b/JASidePanels/Source/JASidePanelController.h
@@ -94,6 +94,9 @@ typedef enum _JASidePanelState {
 // by default applies rounded corners to the panel. override in sublcass to change
 - (void)stylePanel:(UIView *)panel;
 
+// This method will be called whenever the sidepanel visible amount change. Subclass this method to react to changes of how much of the center panel / side panels are visible
+- (void)willPanToSidePanelVisiblePercent:(CGFloat)percent duration:(CGFloat)duration;
+
 #pragma mark - Animation
 
 // the minimum % of total screen width the centerPanel.view must move for panGesture to succeed
diff --git a/JASidePanels/Source/JASidePanelController.m b/JASidePanels/Source/JASidePanelController.m
index 811dd5c..bc4c247 100644
--- a/JASidePanels/Source/JASidePanelController.m
+++ b/JASidePanels/Source/JASidePanelController.m
@@ -516,8 +516,10 @@ - (void)_handlePan:(UIGestureRecognizer *)sender {
         if (self.style == JASidePanelMultipleActive || self.pushesSidePanels) {
             [self _layoutSideContainers:NO duration:0];
         }
-        
-        if (sender.state == UIGestureRecognizerStateEnded) {
+        if(sender.state == UIGestureRecognizerStateChanged) {
+            CGFloat fullyVisibleWidth = frame.origin.x > 0.0f ? self.leftVisibleWidth : -self.rightVisibleWidth;
+            [self willPanToSidePanelVisiblePercent:(frame.origin.x / fullyVisibleWidth) duration:0.0f];
+        } else if (sender.state == UIGestureRecognizerStateEnded) {
             CGFloat deltaX =  frame.origin.x - _locationBeforePan.x;			
             if ([self _validateThreshold:deltaX]) {
                 [self _completePan:deltaX];
@@ -567,6 +569,8 @@ - (void)_undoPan {
     }
 }
 
+- (void)willPanToSidePanelVisiblePercent:(CGFloat)percent duration:(CGFloat)duration {}
+
 #pragma mark - Tap Gesture
 
 - (void)setTapView:(UIView *)tapView {
@@ -738,6 +742,8 @@ - (void)_animateCenterPanel:(BOOL)shouldBounce completion:(void (^)(BOOL finishe
     }
     
     CGFloat duration = [self _calculatedDuration];
+    CGFloat sidePanelVisiblePercent = _centerPanelRestingFrame.origin.x == 0.0f ? 0.0f : 1.0f;
+    [self willPanToSidePanelVisiblePercent:sidePanelVisiblePercent duration:duration];
     [UIView animateWithDuration:duration delay:0.0f options:UIViewAnimationOptionCurveLinear|UIViewAnimationOptionLayoutSubviews animations:^{
         self.centerPanelContainer.frame = _centerPanelRestingFrame;
         [self styleContainer:self.centerPanelContainer animate:YES duration:duration];
@@ -829,6 +835,7 @@ - (void)_showLeftPanel:(BOOL)animated bounce:(BOOL)shouldBounce {
     if (animated) {
         [self _animateCenterPanel:shouldBounce completion:nil];
     } else {
+        [self willPanToSidePanelVisiblePercent:1.0f duration:0.0f];
         self.centerPanelContainer.frame = _centerPanelRestingFrame;	
         [self styleContainer:self.centerPanelContainer animate:NO duration:0.0f];
         if (self.style == JASidePanelMultipleActive || self.pushesSidePanels) {
@@ -851,6 +858,7 @@ - (void)_showRightPanel:(BOOL)animated bounce:(BOOL)shouldBounce {
     if (animated) {
         [self _animateCenterPanel:shouldBounce completion:nil];
     } else {
+        [self willPanToSidePanelVisiblePercent:1.0f duration:0.0f];
         self.centerPanelContainer.frame = _centerPanelRestingFrame;	
         [self styleContainer:self.centerPanelContainer animate:NO duration:0.0f];
         if (self.style == JASidePanelMultipleActive || self.pushesSidePanels) {
@@ -876,6 +884,7 @@ - (void)_showCenterPanel:(BOOL)animated bounce:(BOOL)shouldBounce {
             [self _unloadPanels];
         }];
     } else {
+        [self willPanToSidePanelVisiblePercent:0.0f duration:0.0f];
         self.centerPanelContainer.frame = _centerPanelRestingFrame;	
         [self styleContainer:self.centerPanelContainer animate:NO duration:0.0f];
         if (self.style == JASidePanelMultipleActive || self.pushesSidePanels) {