拖放动画反冲回源

Question

将动画从一个NSTableView拖放到另一个窗口的NSTextView会返回到源代码视图，而不是文本视图。拖放操作可以正常工作，否则我的数据将被粘贴。我的NSTextView的子类拥有所有的拖放协议方法(参见下面的代码)。可能出了什么问题？

- (void)awakeFromNib { // Adjust default insets
[self setTextViewInset];
[self registerForDraggedTypes:[NSArray arrayWithObjects:AWNDragNDropGeneralRuleRecordType, nil]]; 
[self registerAsObserver];
}

- (void)registerAsObserver
{
    [self addObserver:scrollerSubclass
           forKeyPath:@"focused"
              options:NSKeyValueObservingOptionNew
              context:NULL];
}

- (BOOL)acceptsFirstResponder
{
    NSLog(@"Accepting");
    [self setFocused:YES];
    return YES;
}

- (BOOL)resignFirstResponder
{
    NSLog(@"Resigning");
    [self setFocused:NO];
    [super resignFirstResponder]; // Otherwise cursor remains in textView
    return YES;
}

- (BOOL)becomeFirstResponder
{
    NSLog(@"Becoming");
    return YES;
}

- (void)setFocused:(BOOL)x
{
    NSLog(@"-setFocused: is called with %d",x);
    focused = x;
}


- (BOOL)focused
{
    NSLog(@"-focused: is returning %d",focused);
    return focused;
}


- (BOOL)prepareForDragOperation:(id <NSDraggingInfo>)sender
{
    NSLog(@"prepareForDragOperation YES");
    return YES;
}


- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender
{
    NSLog(@"draggingEntered:");
    if ([sender draggingSource] == self) {
        return NSDragOperationNone;
    }

    return NSDragOperationCopy;
}


- (void)draggingExited:(id <NSDraggingInfo>)sender
{
    NSLog(@"Draging Exited:");
    [self setNeedsDisplay:YES];
}


- (void)draggingEnded:(id < NSDraggingInfo >)sender
{
    [self performDragOperation:sender];     
}

- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender
{ // Look for drag source in 'SpellRuleFiles.SpellRulesWindowDelegate tableView delegate method
    NSPasteboard *pb = [sender draggingPasteboard];

    if (![self readFromPasteboard:pb]) {
        NSLog(@"Error: Could not read from dragging pasteboard");
        NSLog(@"performDragOperation NO");
        return NO;
    }
    NSLog(@"performDragOperation YES");
    return YES;
}


- (BOOL)readFromPasteboard:(NSPasteboard *)pb 
{ // Source of paste data is 'SpellRuleFile's ' 

    // I'm not showing this code

    return YES;     
}

- (void)concludeDragOperation:(id <NSDraggingInfo>)sender
{
    NSLog(@"conclude drag operation:");
    [self setNeedsDisplay:YES];
}

Answer 1

在-prepareForDragOperation中:你想设置sender.animatesToDestination = NO，在这种情况下，被拖拽的东西在你放下它们时就会消失，而不是往回缩。

或者，如果你想要更好但更复杂的东西，你可以使用-enumerateDraggingItemsWithOptions:etc:etc:遍历放到文本视图中的每一项，并适当地设置它们的draggingFrame，在这种情况下，被拖动的东西将动画显示到你选择的最终目的地。