Question

我正试图在NSTextView中获取所选范围的方向。换句话说，当您使用shift+leftarrow和shift+rightarrow时，所选范围是否会更改其位置或长度。我的第一个问题是selectionAffinity表示方向，但它似乎只适用于多行选择。

如何获得所选范围的方向？

Answer 1

iOS

第1步：声明属性

@property (nonatomic) NSRange lastRange;

步骤2：在TextView Delegate中，添加：

- (void) textViewDidChangeSelection:(UITextView *)textView

    NSRange currentRange = NSMakeRange(textView.selectedRange.location, textView.selectedRange.length);

    if (currentRange.length == 0) {
        NSLog(@"Nothing selected");
        _lastRange = currentRange;
    }
    else {
        if (currentRange.location < _lastRange.location) {
            NSLog(@"Selecting LEFT");
        }
        else {
            NSLog(@"Selecting RIGHT");
        }
    }
}

OSX

OSX具有所需的所有功能，需要更多的工作，但这就是我想出的一个可行的，一致的解决方案。重命名是可选的，或者更确切地说......鼓励...

第1步：对NSTextView进行子类化

在SubClass.h：

中

#import <Cocoa/Cocoa.h>

@interface TheSelectionizer : NSTextView

@property (nonatomic) NSRange lastAnchorPoint;

@end

在SubClass.m

中

#import "TheSelectionizer.h"

- (void)setSelectedRange:(NSRange)charRange affinity:(NSSelectionAffinity)affinity stillSelecting:(BOOL)stillSelectingFlag {

    if (charRange.length == 0) {
        _lastAnchorPoint = charRange;
    }
    [super setSelectedRange:charRange affinity:affinity stillSelecting:stillSelectingFlag];
}

@end

第2步：实现NSTextViewDelegate

- (NSRange) textView:(NSTextView *)textView willChangeSelectionFromCharacterRange:(NSRange)oldSelectedCharRange toCharacterRange:(NSRange)newSelectedCharRange {

    if (newSelectedCharRange.length != 0) {

        TheSelectionizer * selectionizer = (TheSelectionizer *)textView;

        int anchorStart = (int)selectionizer.lastAnchorPoint.location;
        int selectionStart = (int)newSelectedCharRange.location;
        int selectionLength = (int)newSelectedCharRange.length;

        /*
         If mouse selects left, and then a user arrows right, or the opposite, anchor point flips.
         */
        int difference = anchorStart - selectionStart;
        if (difference > 0 && difference != selectionLength) {
            if (oldSelectedCharRange.location == newSelectedCharRange.location) {
                // We were selecting left via mouse, but now we are selecting to the right via arrows
                anchorStart = selectionStart;
            }
            else {
                // We were selecting right via mouse, but now we are selecting to the left via arrows
                anchorStart = selectionStart + selectionLength;
            }
            selectionizer.lastAnchorPoint = NSMakeRange(anchorStart, 0);
        }

        // Evaluate Selection Direction
        if (anchorStart == selectionStart) {
            if (oldSelectedCharRange.length < newSelectedCharRange.length) {
                // Bigger
                NSLog(@"Will select right in overall right selection");
            }
            else {
                // Smaller
                NSLog(@"Will select left in overall right selection");
            }
        }
        else {
            if (oldSelectedCharRange.length < newSelectedCharRange.length) {
                // Bigger
                NSLog(@"Will select left in overall left selection");
            }
            else {
                // Smaller
                NSLog(@"Will select right in overall left selection");
            }
        }
    }

    return newSelectedCharRange;
}

我发布了一个项目，以防万一有人想尝试或希望看到它。

完整＆＃34;项目＆＃34;可用HERE

Answer 2

假设声明了NSRange yourPreviousRange。

//Check when NSTextView changed its value
@interface delegateAppDelegate : NSObject <NSApplicationDelegate, NSTextViewDelegate> {
    NSWindow *window;
}

-(void)textDidChange:(NSNotification *)notification {
    NSRange yourRange = notification.object.selectedRange;
    if (yourRange.location == yourPreviousRange.location - 1 || yourRange.length == yourPreviousRange.length){
     //left direction  
    } else if (yourRange.location == yourPreviousRange.location || yourRange.length == yourPreviousRange.length + 1){
    //right direction
    }
    yourPreviousRange = yourRange;
}

Answer 3

使用NSTextViewDelegate方法：如果您需要多项选择支持，请-textView:willChangeSelectionFromCharacterRange:toCharacterRange:或-textView:willChangeSelectionFromCharacterRanges:toCharacterRanges:。

请注意，如果您仅实施-textView:willChangeSelectionFromCharacterRange:toCharacterRange:，则不允许进行多项选择。

例如，没有多选：

- (NSRange)textView:(NSTextView *)aTextView willChangeSelectionFromCharacterRange:(NSRange)oldSelectedCharRange toCharacterRange:(NSRange)newSelectedCharRange
{
    if (newSelectedCharRange.length == 0 && oldSelectedCharRange.length == 0) 
    {
        /* move the insertion point */

        if (newSelectedCharRange.location < oldSelectedCharRange.location)
            NSLog(@"insertion point move left");
        else
            NSLog(@"insertion point move right");
    }
    else if (newSelectedCharRange.length == 0 && oldSelectedCharRange.length != 0)
    {
        /* end a selection and move insertion point */

        if (newSelectedCharRange.location == oldSelectedCharRange.location)
            NSLog(@"insertion point at start from previous selection");
        else if (newSelectedCharRange.location < oldSelectedCharRange.location)
            NSLog(@"insertion point move left");
        else
            NSLog(@"insertion point move right");
    }
    else if (oldSelectedCharRange.length == 0 && newSelectedCharRange.length != 0)
    {
        /* start a selection */

        if (newSelectedCharRange.location == oldSelectedCharRange.location)
            NSLog(@"start a selection at insertion point, move right");
        else if (newSelectedCharRange.location < oldSelectedCharRange.location)
            NSLog(@"start a selection, move left");
        else
            NSLog(@"start a selection, move right");
    }
    else
    {
        if (newSelectedCharRange.location < oldSelectedCharRange.location)
            NSLog(@"selection move left");
        else
            NSLog(@"selection move right");
    }

    return newSelectedCharRange;
}

如何获取NSTextView的选择方向？

3 个答案:

iOS

OSX