Mod: Allow JotViewControllerDelegate To Know When Drawing Happens

jot/JotTouchBezier.m

@@ -23,14 +23,14 @@ + (instancetype)withColor:(UIColor *)color
 
 - (void)jotDrawBezier
 {
-    if (self.constantWidth) {
+    if (self.constantWidth || [self isErasing]) {
         UIBezierPath *bezierPath = [UIBezierPath new];
         [bezierPath moveToPoint:self.startPoint];
         [bezierPath addCurveToPoint:self.endPoint controlPoint1:self.controlPoint1 controlPoint2:self.controlPoint2];
         bezierPath.lineWidth = self.startWidth;
         bezierPath.lineCapStyle = kCGLineCapRound;
         [self.strokeColor setStroke];
-        [bezierPath strokeWithBlendMode:kCGBlendModeNormal alpha:1.f];
+        [bezierPath strokeWithBlendMode:([self isErasing])?kCGBlendModeClear:kCGBlendModeNormal alpha:1.f];
     } else {
         [self.strokeColor setFill];
 
@@ -61,13 +61,17 @@ - (void)jotDrawBezier
     }
 }
 
+- (Boolean) isErasing {
+    return [self.strokeColor isEqual: [UIColor clearColor]];
+}
+
 + (void)jotDrawBezierPoint:(CGPoint)point withWidth:(CGFloat)width
 {
     CGContextRef context = UIGraphicsGetCurrentContext();
     if (!context) {
         return;
     }
-    
+
     CGContextFillEllipseInRect(context, CGRectInset(CGRectMake(point.x, point.y, 0.f, 0.f), -width / 2.f, -width / 2.f));
 }
 

jot/JotViewController.h

@@ -175,6 +175,16 @@ typedef NS_ENUM(NSUInteger, JotViewState){
  */
 - (void)clearText;
 
+/**
+ * Enter 'Erase' mode. User touch interaction will erase drawing
+ */
+- (void)startErasingDrawing;
+
+/**
+ * Enter normal drawing mode
+ */
+- (void)endErasingDrawing;
+
 /**
  *  Overlays the drawing and text on the given background image at the full
  *  resolution of the image.
@@ -215,6 +225,12 @@ typedef NS_ENUM(NSUInteger, JotViewState){
  */
 - (UIImage *)renderImageWithScale:(CGFloat)scale onColor:(UIColor *)color;
 
+-(void) startTouchAtPoint:(CGPoint) point withColor:(UIColor *) color;
+
+-(void) moveTouchToPoint:(CGPoint) point withColor:(UIColor *) color;
+
+-(void) endTouch;
+
 @end
 
 @protocol JotViewControllerDelegate <NSObject>
@@ -229,4 +245,26 @@ typedef NS_ENUM(NSUInteger, JotViewState){
  */
 - (void)jotViewController:(JotViewController *)jotViewController isEditingText:(BOOL)isEditing;
 
+/**
+ * Called whenever the user begins a stroke in JotDrawView
+ * @param jotViewController  The  JotDrawViewController to which the delegate is associated
+ * @param point the point of the touch
+ * @param color the current stroke color
+ */
+-(void) jotViewController:(JotViewController *)jotViewController touchesBeganAtPoint:(CGPoint)point color:(UIColor *) color;
+
+/**
+ * Called whenever the user is drawing a stroke
+ * @param jotViewController  The  JotDrawViewController to which the delegate is associated
+ * @param point the point of the touch
+ * @param color the current stroke color
+ */
+-(void) jotViewController:(JotViewController *)jotViewController touchesMovedToPoint:(CGPoint)point color:(UIColor *) color;
+
+/**
+ * Called whenever the user completes a stroke
+ * @param jotViewController  The  JotDrawViewController to which the delegate is associated
+ */
+-(void) jotViewControllerTouchesEnded:(JotViewController *)jotViewController;
+
 @end

jot/JotViewController.m

@@ -24,6 +24,7 @@ @interface JotViewController () <UIGestureRecognizerDelegate, JotTextEditViewDel
 @property (nonatomic, strong) JotDrawView *drawView;
 @property (nonatomic, strong) JotTextEditView *textEditView;
 @property (nonatomic, strong) JotTextView *textView;
+@property (nonatomic, strong) NSMutableDictionary *eraseProperties;
 
 @end
 
@@ -38,6 +39,7 @@ - (instancetype)init
         _textEditView.delegate = self;
         _textView = [JotTextView new];
         _drawingContainer = [JotDrawingContainer new];
+        _eraseProperties = [NSMutableDictionary dictionary];
         self.drawingContainer.delegate = self;
 
         _font = self.textView.font;
@@ -243,6 +245,22 @@ - (void)setDrawingConstantStrokeWidth:(BOOL)drawingConstantStrokeWidth
     }
 }
 
+#pragma mark - external draw point handlers
+-(void) startTouchAtPoint:(CGPoint) point withColor:(UIColor *) color {
+    self.drawView.strokeColor = color;
+    [self.drawView drawTouchBeganAtPoint:point];
+}
+
+-(void) moveTouchToPoint:(CGPoint) point withColor:(UIColor *) color {
+    self.drawView.strokeColor = color;
+    [self.drawView drawTouchMovedToPoint:point];
+}
+
+-(void) endTouch {
+    [self.drawView drawTouchEnded];
+}
+
+
 #pragma mark - Undo
 
 - (void)clearAll
@@ -262,6 +280,22 @@ - (void)clearText
     [self.textView clearText];
 }
 
+- (void)startErasingDrawing {
+    self.eraseProperties[@"color"] = self.drawingColor;
+    self.eraseProperties[@"strokeWidth"] = @(self.drawingStrokeWidth);
+    self.eraseProperties[@"constantStrokeWidth"] = @(self.drawingConstantStrokeWidth);
+    [self setDrawingColor:[UIColor clearColor]];
+    [self setDrawingStrokeWidth:30.f];
+    [self setDrawingConstantStrokeWidth:YES];
+}
+
+- (void)endErasingDrawing {
+    [self setDrawingColor:self.eraseProperties[@"color"]];
+    [self setDrawingStrokeWidth:[self.eraseProperties[@"strokeWidth"] floatValue]];
+    [self setDrawingConstantStrokeWidth: [self.eraseProperties[@"constantStrokeWidth"] boolValue]];
+    [self.eraseProperties removeAllObjects];
+}
+
 #pragma mark - Output UIImage
 
 - (UIImage *)drawOnImage:(UIImage *)image
@@ -335,20 +369,26 @@ - (void)jotDrawingContainerTouchBeganAtPoint:(CGPoint)touchPoint
 {
     if (self.state == JotViewStateDrawing) {
         [self.drawView drawTouchBeganAtPoint:touchPoint];
+        if([self.delegate respondsToSelector:@selector(jotViewController:touchesBeganAtPoint:color:)])
+            [self.delegate jotViewController:self touchesBeganAtPoint:touchPoint color: self.drawingColor];
     }
 }
 
 - (void)jotDrawingContainerTouchMovedToPoint:(CGPoint)touchPoint
 {
     if (self.state == JotViewStateDrawing) {
         [self.drawView drawTouchMovedToPoint:touchPoint];
+        if([self.delegate respondsToSelector:@selector(jotViewController:touchesMovedToPoint:color:)])
+            [self.delegate jotViewController:self touchesMovedToPoint:touchPoint color: self.drawingColor];
     }
 }
 
 - (void)jotDrawingContainerTouchEnded
 {
     if (self.state == JotViewStateDrawing) {
         [self.drawView drawTouchEnded];
+        if([self.delegate respondsToSelector:@selector(jotViewControllerTouchesEnded:)])
+            [self.delegate jotViewControllerTouchesEnded:self];
     }
 }