add support for text attachments

enormego · Aug 29, 2011 · d8622cc · d8622cc
1 parent 6b345f5
commit d8622cc
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diff --git a/EGOTextView/EGOTextView.h b/EGOTextView/EGOTextView.h
@@ -27,6 +27,10 @@
 #import <UIKit/UITextChecker.h>
 #include <objc/runtime.h>
 
+
+extern NSString * const EGOTextAttachmentAttributeName;
+extern NSString * const EGOTextAttachmentPlaceholderString;
+
 @class EGOTextView;
 @protocol EGOTextViewDelegate <NSObject, UIScrollViewDelegate>
 @optional
@@ -45,6 +49,18 @@
 
 @end
 
+@protocol EGOTextAttachmentCell <NSObject>
+@optional
+
+// the attachment must either implement -attachmentView or both
+// -attachmentSize and -attachmentDrawInRect:
+- (UIView *)attachmentView;
+
+- (CGSize) attachmentSize;
+- (void) attachmentDrawInRect: (CGRect)r;
+
+@end
+
 @class EGOCaretView, EGOContentView, EGOTextWindow, EGOMagnifyView, EGOSelectionView;
 @interface EGOTextView : UIScrollView <UITextInputTraits, UITextInput> {
 @private
@@ -84,6 +100,8 @@
     EGOCaretView        *_caretView;
     EGOSelectionView    *_selectionView;
 
+    NSMutableArray      *_attachmentViews;
+
 }
 
 @property(nonatomic) UIDataDetectorTypes dataDetectorTypes; // UIDataDetectorTypeLink supported

diff --git a/EGOTextView/EGOTextView.m b/EGOTextView/EGOTextView.m
@@ -26,6 +26,9 @@
 #import "EGOTextView.h"
 #import <QuartzCore/QuartzCore.h>
 
+NSString * const EGOTextAttachmentAttributeName = @"com.enormego.EGOTextAttachmentAttribute";
+NSString * const EGOTextAttachmentPlaceholderString = @"\uFFFC";
+
 typedef enum {
     EGOWindowLoupe = 0,
     EGOWindowMagnify,
@@ -36,6 +39,28 @@
     EGOSelectionTypeRight,
 } EGOSelectionType;
 
+// MARK: Text attachment helper functions
+static void AttachmentRunDelegateDealloc(void *refCon) {
+    [(id)refCon release];
+}
+
+static CGSize AttachmentRunDelegateGetSize(void *refCon) {
+    id <EGOTextAttachmentCell> cell = refCon;
+    if ([cell respondsToSelector: @selector(attachmentSize)]) {
+        return [cell attachmentSize];
+    } else {
+        return [[cell attachmentView] frame].size;
+    }
+}
+
+static CGFloat AttachmentRunDelegateGetDescent(void *refCon) {
+    return AttachmentRunDelegateGetSize(refCon).height;
+}
+
+static CGFloat AttachmentRunDelegateGetWidth(void *refCon) {
+    return AttachmentRunDelegateGetSize(refCon).width;
+}
+
 // MARK: EGOContentView definition
 
 @interface EGOContentView : UIView {
@@ -145,6 +170,7 @@ - (void)removeCorrectionAttributesForRange:(NSRange)range;
 - (void)insertCorrectionAttributesForRange:(NSRange)range;
 - (void)showCorrectionMenuForRange:(NSRange)range;
 - (void)checkLinksForRange:(NSRange)range;
+- (void)scanAttachments;
 - (void)showMenu;
 - (CGRect)menuPresentationRect;
 
@@ -303,6 +329,22 @@ - (void)textChanged {
         CFRelease(frameRef);
     }
 
+    for (UIView *view in _attachmentViews) {
+        [view removeFromSuperview];
+    }
+    [_attributedString enumerateAttribute: EGOTextAttachmentAttributeName inRange: NSMakeRange(0, [_attributedString length]) options: 0 usingBlock: ^(id value, NSRange range, BOOL *stop) {
+
+        if ([value respondsToSelector: @selector(attachmentView)]) {
+            UIView *view = [value attachmentView];
+            [_attachmentViews addObject: view];
+
+            CGRect rect = [self firstRectForNSRange: range];
+            rect.size = [view frame].size;
+            [view setFrame: rect];
+            [self addSubview: view];
+        }
+    }];
+
     [_textContentView setNeedsDisplay];
 
 }
@@ -348,6 +390,7 @@ - (void)setAttributedString:(NSAttributedString*)string {
     NSRange range = NSMakeRange(0, _attributedString.string.length);
     if (!_editing && !_editable) {
         [self checkLinksForRange:range];
+        [self scanAttachments];
     }
 
     [self textChanged];
@@ -550,6 +593,25 @@ - (void)drawContentInRect:(CGRect)rect {
         CTLineRef line = (CTLineRef)CFArrayGetValueAtIndex((CFArrayRef)lines, i);
         CGContextSetTextPosition(ctx, frameRect.origin.x + origins[i].x, frameRect.origin.y + origins[i].y);
         CTLineDraw(line, ctx);
+
+        CFArrayRef runs = CTLineGetGlyphRuns(line);
+        CFIndex runsCount = CFArrayGetCount(runs);
+        for (CFIndex runsIndex = 0; runsIndex < runsCount; runsIndex++) {
+            CTRunRef run = CFArrayGetValueAtIndex(runs, runsIndex);
+            CFDictionaryRef attributes = CTRunGetAttributes(run);
+            id <EGOTextAttachmentCell> attachmentCell = [(id)attributes objectForKey: EGOTextAttachmentAttributeName];
+            if (attachmentCell != nil && [attachmentCell respondsToSelector: @selector(attachmentSize)] && [attachmentCell respondsToSelector: @selector(attachmentDrawInRect:)]) {
+                CGPoint position;
+                CTRunGetPositions(run, CFRangeMake(0, 1), &position);
+
+                CGSize size = [attachmentCell attachmentSize];
+                CGRect rect = { { origins[i].x + position.x, origins[i].y + position.y }, size };
+
+                UIGraphicsPushContext(UIGraphicsGetCurrentContext());
+                [attachmentCell attachmentDrawInRect: rect];
+                UIGraphicsPopContext();
+            }
+        }
 	}
     free(origins);
 
@@ -1478,6 +1540,38 @@ - (void)checkLinksForRange:(NSRange)range {
 
 }
 
+- (void)scanAttachments {
+
+    __block NSMutableAttributedString *mutableAttributedString = nil;
+
+    [_attributedString enumerateAttribute: EGOTextAttachmentAttributeName inRange: NSMakeRange(0, [_attributedString length]) options: 0 usingBlock: ^(id value, NSRange range, BOOL *stop) {
+        // we only care when an attachment is set
+        if (value != nil) {
+            // create the mutable version of the string if it's not already there
+            if (mutableAttributedString == nil)
+                mutableAttributedString = [_attributedString mutableCopy];
+
+            CTRunDelegateCallbacks callbacks = {
+                .version = kCTRunDelegateVersion1,
+                .dealloc = AttachmentRunDelegateDealloc,
+                .getAscent = AttachmentRunDelegateGetDescent,
+                //.getDescent = AttachmentRunDelegateGetDescent,
+                .getWidth = AttachmentRunDelegateGetWidth
+            };
+
+            // the retain here is balanced by the release in the Dealloc function
+            CTRunDelegateRef runDelegate = CTRunDelegateCreate(&callbacks, [value retain]);
+            [mutableAttributedString addAttribute: (NSString *)kCTRunDelegateAttributeName value: (id)runDelegate range:range];
+            CFRelease(runDelegate);
+        }
+    }];
+
+    if (mutableAttributedString) {
+        [_attributedString release];
+        _attributedString = mutableAttributedString;
+    }
+}
+
 - (BOOL)selectedLinkAtIndex:(NSInteger)index {
 
     NSTextCheckingResult *_link = [self linkAtIndex:index];