objective-c – 如何获取NSTextView的选择方向？

概述我试图在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.我的第一个虽然是selectionAffinity表示方向,但它似乎只适用于多行选择. 如何获得选定范围的方向？ iOS版 步骤1：声明属性 @property (nonatomic) NSRange lastRange; 步骤2： 我试图在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.我的第一个虽然是selectionAffinity表示方向,但它似乎只适用于多行选择.

如何获得选定范围的方向？

解决方法 iOS版

步骤1：声明属性

@property (nonatomic) NSRange lastRange;

步骤2：在TextVIEw代理中,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,但这是我想出了一个工作,一致的解决方案.重命名是可选的,或者…鼓励…

第1步：将NSTextVIEw子类化

在你的SubClass.h中：

#import <Cocoa/Cocoa.h>@interface TheSelectionizer : NSTextVIEw@property (nonatomic) NSRange lastAnchorPoint;@end

在你的SubClass.m

#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

步骤2：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,以防有人想尝试或想要看到它.

完整的“项目”可用HERE

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