Merge pull request slackhq#33 from slackhq/undo-redo-support

Undo/Redo support

Author: Ignacio Romero Z.

Examples/Messenger/Messenger/MessageViewController.m

@@ -112,7 +112,7 @@ - (void)fillWithText:(id)sender
         self.textView.text = [LoremIpsum sentencesWithNumber:sentences];
     }
     else {
-        [self.textView slk_insertTextAtCaretRange:[LoremIpsum word]];
+        [self.textView slk_insertTextAtCaretRange:[NSString stringWithFormat:@" %@", [LoremIpsum word]]];
     }
 }
 
@@ -143,6 +143,10 @@ - (void)editRandomMessage:(id)sender
 
 - (void)editLastMessage:(id)sender
 {
+    if (self.textView.text > 0) {
+        return;
+    }
+    
     NSString *lastMessage = [self.messages firstObject];
     [self editText:lastMessage];
 

Source/Additions/UITextView+SLKAdditions.h

@@ -63,4 +63,11 @@
  */
 - (NSString *)slk_wordAtCaretRange:(NSRangePointer)range;
 
+/**
+ Registers the current text for future undo actions.
+ 
+ @param description A simple description associated with the Undo or Redo command.
+ */
+- (void)prepareForUndo:(NSString *)description;
+
 @end

Source/Additions/UITextView+SLKAdditions.m

@@ -94,6 +94,9 @@ - (NSRange)slk_insertText:(NSString *)text inRange:(NSRange)range
         return NSMakeRange(0, 0);
     }
 
+    // Registers for undo management
+    [self prepareForUndo:@"Text appending"];
+    
     // Append the new string at the caret position
     if (range.length == 0)
     {
@@ -164,4 +167,10 @@ - (NSString *)slk_wordAtRange:(NSRange)range rangeInText:(NSRangePointer)rangePo
     return word;
 }
 
+- (void)prepareForUndo:(NSString *)description
+{
+    [[self.undoManager prepareWithInvocationTarget:self] setText:self.text];
+    [self.undoManager setActionName:description];
+}
+
 @end

Source/Classes/SLKTextInputbar.m

@@ -36,6 +36,7 @@ @interface SLKTextInputbar () <UITextViewDelegate>
 @property (nonatomic, strong) NSLayoutConstraint *accessoryViewHC;
 
 @property (nonatomic, strong) UILabel *charCountLabel;
+@property (nonatomic) BOOL newWordInserted;
 
 @end
 
@@ -126,6 +127,11 @@ - (SLKTextView *)textView
                 [gesture addTarget:self action:@selector(willShowLoupe:)];
             }
         }
+        
+        // Registers the Menu Controller for undo/redo actions
+        UIMenuItem *undo = [[UIMenuItem alloc] initWithTitle:@"Undo" action:NSSelectorFromString(@"undo:")];
+        UIMenuItem *redo = [[UIMenuItem alloc] initWithTitle:@"Redo" action:NSSelectorFromString(@"redo:")];
+        [[UIMenuController sharedMenuController] setMenuItems:@[undo,redo]];
     }
     return _textView;
 }
@@ -364,13 +370,13 @@ - (void)updateCounter
     NSString *counter = nil;
 
     if (self.counterStyle == SLKCounterStyleNone) {
-        counter = [NSString stringWithFormat:@"%ld", text.length];
+        counter = [NSString stringWithFormat:@"%ld", (unsigned long)text.length];
     }
     if (self.counterStyle == SLKCounterStyleSplit) {
-        counter = [NSString stringWithFormat:@"%ld/%ld", text.length, self.maxCharCount];
+        counter = [NSString stringWithFormat:@"%ld/%ld", (unsigned long)text.length, (unsigned long)self.maxCharCount];
     }
     if (self.counterStyle == SLKCounterStyleCountdown) {
-        counter = [NSString stringWithFormat:@"%ld", text.length-self.maxCharCount];
+        counter = [NSString stringWithFormat:@"%u", text.length-self.maxCharCount];
     }
 
     self.charCountLabel.text = counter;
@@ -411,6 +417,13 @@ - (BOOL)textViewShouldEndEditing:(UITextView *)textView
 
 - (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
 {
+    self.newWordInserted = ([text rangeOfCharacterFromSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]].location != NSNotFound);
+    
+    // Records text for undo for every new word
+    if (self.newWordInserted) {
+        [self.textView prepareForUndo:@"Word Change"];
+    }
+    
     if ([text isEqualToString:@"\n"]) {
         //Detected break. Should insert new line break manually.
         [textView slk_insertNewLineBreak];

Source/Classes/SLKTextView.m

@@ -193,13 +193,19 @@ - (void)setPlaceholderColor:(UIColor *)color
 
 - (void)setText:(NSString *)text
 {
+    // Registers for undo management
+    [self prepareForUndo:@"Text Set"];
+    
     [super setText:text];
 
     [[NSNotificationCenter defaultCenter] postNotificationName:UITextViewTextDidChangeNotification object:self];
 }
 
 - (void)setAttributedText:(NSAttributedString *)attributedText
 {
+    // Registers for undo management
+    [self prepareForUndo:@"Attributed Text Set"];
+    
     [super setAttributedText:attributedText];
 }
 
@@ -213,6 +219,11 @@ - (BOOL)canPerformAction:(SEL)action withSender:(id)sender
         return YES;
     }
 
+    if ((action == @selector(undo:) && [self.undoManager canUndo]) ||
+        (action == @selector(redo:) && [self.undoManager canRedo])) {
+        return YES;
+    }
+    
     return [super canPerformAction:action withSender:sender];
 }
 
@@ -231,6 +242,16 @@ - (void)paste:(id)sender
     }
 }
 
+- (void)undo:(id)sender
+{
+    [self.undoManager undo];
+}
+
+- (void)redo:(id)sender
+{
+    [self.undoManager redo];
+}
+
 - (void)setFont:(UIFont *)font
 {
     [super setFont:font];

Source/Classes/SLKTextViewController.m

@@ -675,6 +675,21 @@ - (void)didPressReturnKey:(id)sender
     [self performRightAction];
 }
 
+- (void)didPressCommandZKeys:(id)sender
+{
+    UIKeyCommand *keyComamnd = (UIKeyCommand *)sender;
+    
+    if ((keyComamnd.modifierFlags & UIKeyModifierShift) > 0) {
+        
+        if ([self.textView.undoManager canRedo]) {
+            [self.textView.undoManager redo];
+        }
+    }
+    else if ([self.textView.undoManager canUndo]) {
+        [self.textView.undoManager undo];
+    }
+}
+
 - (void)didPressEscapeKey:(id)sender
 {
     if (self.isAutoCompleting) {
@@ -1240,6 +1255,14 @@ - (NSArray *)keyCommands
                                  modifierFlags:UIKeyModifierControl
                                         action:@selector(insertNewLineBreak)],
 
+             // Undo/Redo
+             [UIKeyCommand keyCommandWithInput:@"z"
+                                 modifierFlags:UIKeyModifierCommand
+                                        action:@selector(didPressCommandZKeys:)],
+             [UIKeyCommand keyCommandWithInput:@"z"
+                                 modifierFlags:UIKeyModifierShift|UIKeyModifierCommand
+                                        action:@selector(didPressCommandZKeys:)],
+             
              // Pressing Esc key
              [UIKeyCommand keyCommandWithInput:UIKeyInputEscape
                                  modifierFlags:0