I'm building a basic text editor with custom controls. For my text alignment control, I need to cover two user scenarios:
the text view is the first responder - make the paragraph attribute changes to textView.rangesForUserParagraphAttributeChange
the text view is not the first responder - make the paragraph attribute changes to the full text range.
Here's the method:
- (IBAction)changedTextAlignment:(NSSegmentedControl *)sender
{
NSTextAlignment align;
// ....
NSRange fullRange = NSMakeRange(0, self.textView.textStorage.length);
NSArray *changeRanges = [self.textView rangesForUserParagraphAttributeChange];
if (![self.mainWindow.firstResponder isEqual:self.textView])
{
changeRanges = #[[NSValue valueWithRange:fullRange]];
}
[self.textView shouldChangeTextInRanges:changeRanges replacementStrings:nil];
[self.textView.textStorage beginEditing];
for (NSValue *r in changeRanges)
{
#try {
NSDictionary *attrs = [self.textView.textStorage attributesAtIndex:r.rangeValue.location effectiveRange:NULL];
NSMutableParagraphStyle *pStyle = [attrs[NSParagraphStyleAttributeName] mutableCopy];
if (!pStyle)
pStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
[pStyle setAlignment:align];
[self.textView.textStorage addAttributes:#{NSParagraphStyleAttributeName: pStyle}
range:r.rangeValue];
}
#catch (NSException *exception) {
NSLog(#"%#", exception);
}
}
[self.textView.textStorage endEditing];
[self.textView didChangeText];
// ....
NSMutableDictionary *typingAttrs = [self.textView.typingAttributes mutableCopy];
NSMutableParagraphStyle *pStyle = typingAttrs[NSParagraphStyleAttributeName];
if (!pStyle)
pStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
[pStyle setAlignment:align];
[typingAttrs setObject:NSParagraphStyleAttributeName forKey:pStyle];
self.textView.typingAttributes = typingAttrs;
}
So both scenarios work fine... BUT undo/redo doesn't work when the change is applied in the 'not-first-responder' scenario. The undo manager pushes something onto its stack (i.e Undo is available in the Edit menu), but invoking undo doesn't change the text. All it does is visibly select the full text range.
How do I appropriately change text view attributes so that undo/redo works regardless of whether the view is first reponder or not?
Thank you in advance!
I'm not sure, but I have two suggestions. One, check the return value from shouldChangeTextInRanges:..., since perhaps the text system is refusing your proposed change; a good idea in any case. Two, I would try to make the not-first-responder case more like the first-responder case in order to try to get it to work; in particular, you might begin by selecting the full range, so that rangesForUserParagraphAttributeChange is then in fact the range that you change the attributes on. A further step in this direction would be to actually momentarily make the textview be the first responder, for the duration of your change. In that case, the two cases should really be identical, I would think. You can restore the first responder as soon as you're done. Not optimal, but it seems that AppKit is making some assumption behind the scenes that you probably just have to work around. Without getting into trying to reproduce the problem and play with it, that's the best I can offer...
The issue is a typo on my part in the code that updates the typingAttributes afterwards. Look here:
//...
NSMutableParagraphStyle *pStyle = typingAttrs[NSParagraphStyleAttributeName];
// ...
Doh! Needs to be really mutable...
//...
NSMutableParagraphStyle *pStyle = [typingAttrs[NSParagraphStyleAttributeName] mutableCopy];
// ...
Related
At the moment I can invert the currently selected items in an NSTableView with:
- (IBAction) doSelectInvert:(id) sender
{
NSIndexSet *set1=[myTable selectedRowIndexes];
NSMutableIndexSet *set2=[[NSMutableIndexSet alloc] init];
NSUInteger nCount=[myTable numberOfRows];
for(NSUInteger n=0;n<nCount;n++)
if(![set1 containsIndex:n]) [set2 addIndex:n];
[myTable selectRowIndexes:set2 byExtendingSelection:NO];
[set2 release];
}
Is this correct, or is there a more elegant way?
The most important improvement you can make is to adopt ARC. This will make your code more elegant by removing extra retain/release calls, and prevent a whole lot of simple errors. It's not fun to track down an extra release call that only sometimes has detectable symptoms.
Looking at all the NSMutableIndexSet methods, there are some more powerful operators, like -removeIndexes:, that can save you a bit of work, compared to building up your set one-at-a-time. Finding a way to use them sometimes means "inverting" your thinking a bit — for example, removing items from the set of everything, instead of adding items to an empty set.
- (IBAction) doSelectInvert:(id) sender
{
// start with all rows
NSRange allRows = NSMakeRange(0, [myTable numberOfRows]);
NSMutableIndexSet *invertedSelection = [NSMutableIndexSet indexSetWithIndexesInRange:allRows];
//then remove the currently selected rows
[invertedSelection removeIndexes:[myTable selectedRowIndexes]];
//set the new selection
[myTable selectRowIndexes:invertedSelection byExtendingSelection:NO];
}
Swift 5 variant, based on Vincent's answer and with feedback from #vadian:
var selection = IndexSet(integersIn: 0...tableView.numberOfRows)
selection.subtract(tableView.selectedRowIndexes)
tableView.selectRowIndexes(selection, byExtendingSelection: false)
Or if you prefer hard to read one liners:
tableView.selectRowIndexes(IndexSet(integersIn: 0...tableView.numberOfRows).subtracting(tableView.selectedRowIndexes), byExtendingSelection: false)
I want to change the color of specific text in NSTextView. The method should check that after a keydown event.
For example: the word void is finished and the string void changes the
color to blue. Like a code editor.
I searched for a long time but don't find anything.
My Code:
NSRange range = [text rangeOfString:#"void"];
NSString *substring = [[text substringFromIndex:NSMaxRange(range)] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
//I think, here is the mistake.
NSAttributedString *now = [NSAttributedString initWithString:substring];
[now setTextColor:[[NSColor blueColor]]];
I have read that i have to use a NSAttributedString but i don't know how I can get this class from a string.
I'am quite new in cocoa programming.
Thanks for every help!
You can do this way:
NSString *str = #"Hello. That is a test attributed string.";
//in place of NSMakeRange put your range
[self.textview setRichText:YES];
[self.textview setString:str];
[self.textview setTextColor:[NSColor redColor] range:NSMakeRange(3,5)];
In an app I'm working on, the user inputs plain text, and the app reformats the text by transforming it to an NSAttributedString, and displays it. This all happens live.
Currently, I'm doing the following on my NSTextView's textDidChange delegate method:
- (void)textDidChange:(NSNotification *)notification {
// saving the cursor position
NSInteger insertionPoint = [[[self.mainTextView selectedRanges] objectAtIndex:0] rangeValue].location;
// this grabs the text view's contact as plain text
[self updateContentFromTextView];
// this creates an attributed strings and displays it
[self updateTextViewFromContent];
// resetting the cursor position
self.mainTextView.selectedRange = NSMakeRange(insertionPoint, 0);
}
While this mostly works, it's not ideal. The text seems to blink for a split second (you especially notice it on the red dots under spelling errors), and when the cursor was previously near one of the edges of the visible rect, it the scroll position gets reset. In my case, this is a very much undesirable side-effect.
So my question is: Is there a better way of doing what I'm trying to do?
I think you have a slight misconception of how an NSTextView works. The user never enters a "plain string", the data store of an NSTextView is always an NSTextStorage object, which is a subclass of NSMutableAttributedString.
What you need to do is add/remove attributes to the existing attributed string that the user is editing, rather than replacing the entire string.
You should also not make changes to the string in the ‑textDidChange: delegate method, as changing the string from that method can cause another change notification.
Instead, you should implement the delegate method ‑textStorageDidProcessEditing:. This is called whenever the text changes. You can then make modifications to the string like so:
- (void)textStorageDidProcessEditing:(NSNotification*)notification
{
//get the text storage object from the notification
NSTextStorage* textStorage = [notification object];
//get the range of the entire run of text
NSRange aRange = NSMakeRange(0, [textStorage length]);
//for example purposes, change all the text to yellow
//remove existing coloring
[textStorage removeAttribute:NSForegroundColorAttributeName range:aRange];
//add new coloring
[textStorage addAttribute:NSForegroundColorAttributeName
value:[NSColor yellowColor]
range:aRange];
}
I'm trying to write a "highlight" feature on an NSTextView. Currently, everything works great. You select a range of text and the background color of that text changes to yellow. However, while it's still selected, the background is that standard blue of selected text. How do I make that standard selection indicator color not show up in certain cases?
Thanks!
Use -[NSTextView setSelectedTextAttributes:...].
For example:
[textView setSelectedTextAttributes:
[NSDictionary dictionaryWithObjectsAndKeys:
[NSColor blackColor], NSBackgroundColorAttributeName,
[NSColor whiteColor], NSForegroundColorAttributeName,
nil]];
You can simply pass an empty dictionary if you don't want the selection indicated in any way at all (short of hiding the insertion point).
Another option is to watch for selection changes and apply the "selection" using temporary attributes. Note that temporary attributes are used to show spelling and grammar mistakes and find results; so if you care about preserving these features of NSTextView then make sure only to add and remove temporary attributes, not replace them.
An example of this is (in a NSTextView subclass):
- (void)setSelectedRanges:(NSArray *)ranges affinity:(NSSelectionAffinity)affinity stillSelecting:(BOOL)stillSelectingFlag;
{
NSArray *oldRanges = [self selectedRanges];
for (NSValue *v in oldRanges) {
NSRange oldRange = [v rangeValue];
if (oldRange.length > 0)
[[self layoutManager] removeTemporaryAttribute:NSBackgroundColorAttributeName forCharacterRange:oldRange];
}
for (NSValue *v in ranges) {
NSRange range = [v rangeValue];
if (range.length > 0)
[[self layoutManager] addTemporaryAttributes:[NSDictionary dictionaryWithObject:[NSColor blueColor] forKey:NSBackgroundColorAttributeName]
forCharacterRange:range];
}
[super setSelectedRanges:ranges affinity:affinity stillSelecting:stillSelectingFlag];
}
Today I have a question that sprouted off of this one: Database Results in Cocoa. It's regarding using the data that was returned by a database to create a certain number of questions. I am using a form of the following code (this was posted in the question).
NSMutableDictionary * interfaceElements = [[NSMutableDictionary alloc] init];
for (NSInteger i = 0; i < numberOfTextFields; ++i) {
//this is just to make a frame that's indented 10px
//and has 10px between it and the previous NSTextField (or window edge)
NSRect frame = NSMakeRect(10, (i*22 + (i+1)*10), 100, 22);
NSTextField * newField = [[NSTextField alloc] initWithFrame:frame];
//configure newField appropriately
[[myWindow contentView] addSubview:newField];
[interfaceElements setObject:newField forKey:#"someUniqueIdentifier"];
[newField release];
}
However, now when I attempt to use IFVerticallyExpandingTextfield (from http://www.cocoadev.com/index.pl?IFVerticallyExpandingTextField), or create any large amount of text, it simply goes over the other drawn content. I looked into using setAutosizingMask: on the object, but it has not worked so far.
Thanks for any help.
EDIT: What I want the effect to look like is called "Correct TextField" and what happens is called "StackOverflow Sample" - http://www.mediafire.com/?sharekey=bd476ea483deded875a4fc82078ae6c8e04e75f6e8ebb871.
EDIT 2: And if no one knows how to use this IFVerticallyExpandingTextfield class, would anyone know if there is another way to accomplish the effect?
Do you mean this?
http://developer.apple.com/documentation/Cocoa/Conceptual/CocoaDrawingGuide/GraphicsContexts/GraphicsContexts.html
Your question is not very clear to me but this might help ^^^.
Look at 'Modifying the Current Graphics State' on that page.
What about just exactly copying the code from the 'Correct textfield' example and use it in your application? Or start your application from the 'Correct texfield' example.
Also
A comment on http://www.cocoadev.com/index.pl?IFVerticallyExpandingTextField says:
Give it a try! You should be able to
throw this into a project, read the
files in Interface Builder, and use
the custom class pane to make an
NSTextField into an
IFVerticallyExpandingTextField. You'll
need to set the layout and
linebreaking attributes for word
wrapping for this to work.
Although expansion should work
properly when the textfield is
embedded in a subview, I'm having some
trouble dealing with NSScrollViews.
The field expands into the
scrollview's content view, but none of
the controls on the scrollbar appear.
Some help here would be appreciated.