上下文：
我有一个普通的基于文档的Cocoa Mac OS X应用程序，它使用NSTextView进行富文本输入。用户可以编辑NSTextView中文本的字体系列，磅值和颜色。
Base SDK：10.7
部署目标：10.6
问题：
我想在用户编辑文本时以编程方式（包括NSTextView）实现整个UI的缩放。缩放NSTextView的框架没有问题。但我不知道如何缩放视图中的可编辑文本，该文本可能在整个文本运行的不同子部分中包含多个不同的点大小。
如何将统一比例因子应用于NSTextView中显示的富文本？
这应该可以很好地与“富文本”一起使用，这样就可以保留用户的字体系列，颜色，特别是点大小（在文本运行的不同点可能会有所不同），但是均匀/相对地缩放。
根据我的Base SDK和部署目标，这可能吗？是否可以使用较新的Base SDK或部署目标？
答案 0 :(得分：10)
如果目的是缩放视图（而不是实际更改字符串中的属性），我建议使用scaleUnitSquareToSize：method：以及ScalingScrollView（可与TextEdit示例代码一起使用）以获得正确的滚动条行为。
ScalingScrollView的核心部分是：
- (void)setScaleFactor:(CGFloat)newScaleFactor adjustPopup:(BOOL)flag
{
CGFloat oldScaleFactor = scaleFactor;
if (scaleFactor != newScaleFactor)
{
NSSize curDocFrameSize, newDocBoundsSize;
NSView *clipView = [[self documentView] superview];
scaleFactor = newScaleFactor;
// Get the frame. The frame must stay the same.
curDocFrameSize = [clipView frame].size;
// The new bounds will be frame divided by scale factor
newDocBoundsSize.width = curDocFrameSize.width / scaleFactor;
newDocBoundsSize.height = curDocFrameSize.height / scaleFactor;
}
scaleFactor = newScaleFactor;
[scale_delegate scaleChanged:oldScaleFactor newScale:newScaleFactor];
}
scale_delegate是您的代理人，可以调整您的NSTextView对象：
- (void) scaleChanged:(CGFloat)oldScale newScale:(CGFloat)newScale
{
NSInteger percent = lroundf(newScale * 100);
CGFloat scaler = newScale / oldScale;
[textView scaleUnitSquareToSize:NSMakeSize(scaler, scaler)];
NSLayoutManager* lm = [textView layoutManager];
NSTextContainer* tc = [textView textContainer];
[lm ensureLayoutForTextContainer:tc];
}
scaleUnitSquareToSize:方法相对于其当前状态进行缩放，因此您可以跟踪比例因子，然后将绝对比例请求（200％）转换为相对比例请求。
答案 1 :(得分：6)
适用于iOS和Mac OS
@implementation NSAttributedString (Scale)
- (NSAttributedString *)attributedStringWithScale:(double)scale
{
if(scale == 1.0)
{
return self;
}
NSMutableAttributedString *copy = [self mutableCopy];
[copy beginEditing];
NSRange fullRange = NSMakeRange(0, copy.length);
[self enumerateAttribute:NSFontAttributeName inRange:fullRange options:0 usingBlock:^(UIFont *oldFont, NSRange range, BOOL *stop) {
double currentFontSize = oldFont.pointSize;
double newFontSize = currentFontSize * scale;
// don't trust -[UIFont fontWithSize:]
UIFont *scaledFont = [UIFont fontWithName:oldFont.fontName size:newFontSize];
[copy removeAttribute:NSFontAttributeName range:range];
[copy addAttribute:NSFontAttributeName value:scaledFont range:range];
}];
[self enumerateAttribute:NSParagraphStyleAttributeName inRange:fullRange options:0 usingBlock:^(NSParagraphStyle *oldParagraphStyle, NSRange range, BOOL *stop) {
NSMutableParagraphStyle *newParagraphStyle = [oldParagraphStyle mutableCopy];
newParagraphStyle.lineSpacing *= scale;
newParagraphStyle.paragraphSpacing *= scale;
newParagraphStyle.firstLineHeadIndent *= scale;
newParagraphStyle.headIndent *= scale;
newParagraphStyle.tailIndent *= scale;
newParagraphStyle.minimumLineHeight *= scale;
newParagraphStyle.maximumLineHeight *= scale;
newParagraphStyle.paragraphSpacing *= scale;
newParagraphStyle.paragraphSpacingBefore *= scale;
[copy removeAttribute:NSParagraphStyleAttributeName range:range];
[copy addAttribute:NSParagraphStyleAttributeName value:newParagraphStyle range:range];
}];
[copy endEditing];
return copy;
}
@end
答案 2 :(得分：1)
OP在这里。
我找到了一种有效的解决方案，并且实施起来并不十分困难。我不确定这是最好/理想的解决方案。我仍然有兴趣寻找其他解决方案。但这是一种方式：
在显示之前手动缩放NSAttributedString源文本的字体磅值和行高多个属性，然后在存储之前取消缩放显示的文本作为来源。
此解决方案的问题在于，在缩放时，系统字体面板将在编辑时显示所选文本的实际缩放显示点大小（而不是“实际”源点大小）。那是不可取的。
这是我的实现：
- (void)scaleAttributedString:(NSMutableAttributedString *)str by:(CGFloat)scale {
if (1.0 == scale) return;
NSRange r = NSMakeRange(0, [str length]);
[str enumerateAttribute:NSFontAttributeName inRange:r options:0 usingBlock:^(NSFont *oldFont, NSRange range, BOOL *stop) {
NSFont *newFont = [NSFont fontWithName:[oldFont familyName] size:[oldFont pointSize] * scale];
NSParagraphStyle *oldParaStyle = [str attribute:NSParagraphStyleAttributeName atIndex:range.location effectiveRange:NULL];
NSMutableParagraphStyle *newParaStyle = [[oldParaStyle mutableCopy] autorelease];
CGFloat oldLineHeight = [oldParaStyle lineHeightMultiple];
CGFloat newLineHeight = scale * oldLineHeight;
[newParaStyle setLineHeightMultiple:newLineHeight];
id newAttrs = @{
NSParagraphStyleAttributeName: newParaStyle,
NSFontAttributeName: newFont,
};
[str addAttributes:newAttrs range:range];
}];
}
这需要在显示之前缩放源文本：
// scale text
CGFloat scale = getCurrentScaleFactor();
[self scaleAttributedString:str by:scale];
然后在存储为源之前反向缩放显示的文本：
// un-scale text
CGFloat scale = 1.0 / getCurrentScaleFactor();
[self scaleAttributedString:str by:scale];
答案 3 :(得分：0)
我要感谢马克·蒙兹（Mark Munz）的回答，因为它使我免于在充满了NSScrollView放大疯狂和NSLayoutManagers的黑暗森林中游荡。
对于仍在寻找的任何人，这是我的方法。此代码位于NSDocument内部。所有文本都被插入到固定宽度和居中的容器中，并且此处的缩放使文字换行等保持完整。无需使用复杂的布局管理，即可创建一种漂亮的“页面视图”外观。
您需要在类中设置CGFloat _documentSize和NSTextView textView常量，此示例才能正常工作。
- (void) initZoom {
// Call this when the view has loaded and is ready
// I am storing a separate _scaleFactor and _magnification for my own purposes, mainly to have the initial scale to be higher than 1.0
_scaleFactor = 1.0;
_magnification = 1.1;
[self setScaleFactor:_magnification adjustPopup:false];
[self updateLayout];
// NOTE: You might need to call updateLayout after the content is set and we know the window size etc.
}
- (void) zoom: (bool) zoomIn {
if (!_scaleFactor) _scaleFactor = _magnification;
// Arbitrary maximum levels of zoom
if (zoomIn) {
if (_magnification < 1.6) _magnification += 0.1;
} else {
if (_magnification > 0.8) _magnification -= 0.1;
}
[self setScaleFactor:_magnification adjustPopup:false];
[self updateLayout];
}
- (void)setScaleFactor:(CGFloat)newScaleFactor adjustPopup:(BOOL)flag
{
CGFloat oldScaleFactor = _scaleFactor;
if (_scaleFactor != newScaleFactor)
{
NSSize curDocFrameSize, newDocBoundsSize;
NSView *clipView = [[self textView] superview];
_scaleFactor = newScaleFactor;
// Get the frame. The frame must stay the same.
curDocFrameSize = [clipView frame].size;
// The new bounds will be frame divided by scale factor
//newDocBoundsSize.width = curDocFrameSize.width / _scaleFactor;
newDocBoundsSize.width = curDocFrameSize.width;
newDocBoundsSize.height = curDocFrameSize.height / _scaleFactor;
NSRect newFrame = NSMakeRect(0, 0, newDocBoundsSize.width, newDocBoundsSize.height);
clipView.frame = newFrame;
}
_scaleFactor = newScaleFactor;
[self scaleChanged:oldScaleFactor newScale:newScaleFactor];
}
- (void) scaleChanged:(CGFloat)oldScale newScale:(CGFloat)newScale
{
CGFloat scaler = newScale / oldScale;
[self.textView scaleUnitSquareToSize:NSMakeSize(scaler, scaler)];
NSLayoutManager* lm = [self.textView layoutManager];
NSTextContainer* tc = [self.textView textContainer];
[lm ensureLayoutForTextContainer:tc];
}
- (void) updateLayout {
CGFloat width = (self.textView.frame.size.width / 2 - _documentWidth * _magnification / 2) / _magnification; self.textView.textContainerInset = NSMakeSize(width, TEXT_INSET_TOP);
self.textView.textContainer.size = NSMakeSize(_documentWidth, self.textView.textContainer.size.height);
}