Platform: MacOS
Language: Objective-C
An extremely performant, completely custom-drawn alternative to NSlider, with a very sensible API.
One of the awesome features of Producer is its ability to capture the frames of data going through a running iOS app that you are building. Producer uses that data to power a feature called Tracer as part of its debugging tools suite, the UI of which contains a horizontal NSSlider with tick marks that lets you scrub through the frames of data. For production apps and bigger projects, this can end up being tens or hundreds of thousands of frames of data, meaning thousands of tick marks in the NSSlider user interface.
We started to notice during stress-testing that Producer would get rather slow when it had to deal with so many data frames. Part of the solution was to optimize our file IO, but it turns out that a surprisingly huge amount of CPU time was being spent by NSSlider doing the drawing for the incredible number of tick marks in the UI.
That's why we created LPDiscreteDrawnSlider. It re-implements all of NSSlider's visual styling and interaction behavior in order to provide a viable alternative for high-demand applications.
We also took the opportunity to simplify the API a bit. :)
To install, simply download the source for this module and include ./DrawnSlider in your Xcode project.
LPDiscreteDrawnSlider is simply a subclass of NSView which implements the drawing and interactions of an NSlider from scratch in a much more highly performant manner. It's styled to look exactly like an incremental NSlider (including enabled state, slider knob interactions, etc.), but it can be completely customized.
All you have to do is create an instance of LPDiscreteDrawnSlider as you would with an NSSlider, like so:
- (void)setup_frameSlider
{
LPDiscreteDrawnSlider *view = [[LPDiscreteDrawnSlider alloc] init];
view.target = self;
view.action = @selector(frameSliderDidAct);
view.frame = [self _new_sliderFrame];
//
self.frameSlider = view;
[self.view addSubview:view];
}
- (NSRect)_new_sliderFrame
{
CGFloat w = self.view.frame.size.width - rightMargin - leftMargin;
CGFloat h = 40;
NSRect frame = NSMakeRect(leftMargin, y, w, h);
//
return frame;
}
To configure and read the slider state aside from target and action, the following methods are available:
- (BOOL)enabled;
- (void)setEnabled:(BOOL)isEnabled;
- (void)setNumberOfTickMarks:(NSUInteger)numberOfTickMarks;
- (NSUInteger)numberOfTickMarks;
- (void)setCurrentSeekIndex:(NSUInteger)currentSeekIndex;
- (NSUInteger)currentSeekIndex;
If you find this code useful and make any expansions to it we encourage you to submit a pull request so that others may get the benefit of your work. Contributors will be credited.