src/views/HoverTableRowView.mm

/*
     File: HoverTableRowView.m
 Abstract: Custom NSTableRowView class for custom drawing and mouse tracking feedback via NSTrackingArea
  Version: 1.1

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#import "HoverTableRowView.h"

#import "NSColor+RingTheme.h"

@interface HoverTableRowView ()
@property BOOL mouseInside;
@end

@implementation HoverTableRowView

@dynamic mouseInside;

- (instancetype)init
{
    self.highlightable = YES;
}

-  (id)initWithFrame:(CGRect)aRect
{
    self = [super initWithFrame:aRect];

    if (self) {
        self.highlightable = YES;
    }

    return self;
}

- (id)initWithCoder:(NSCoder*)aDecoder
{
    self = [super initWithCoder:aDecoder];
    if (self) {
        self.highlightable = YES;
    }

    return self;
}

- (void)dealloc {

}

- (void)setMouseInside:(BOOL)value {
    if (mouseInside != value) {
        mouseInside = value;
        [self setNeedsDisplay:YES];
    }
}

- (BOOL)mouseInside {
    return mouseInside;
}

- (void)ensureTrackingArea {
    if (trackingArea == nil) {
        trackingArea = [[NSTrackingArea alloc] initWithRect:NSZeroRect
                                                    options:NSTrackingInVisibleRect
                        | NSTrackingActiveAlways
                        | NSTrackingMouseEnteredAndExited owner:self userInfo:nil];
    }
}

- (void)updateTrackingAreas {
    [super updateTrackingAreas];
    [self ensureTrackingArea];
    if (![[self trackingAreas] containsObject:trackingArea]) {
        [self addTrackingArea:trackingArea];
    }
}

- (void)mouseEntered:(NSEvent *)theEvent {
    self.mouseInside = YES;
}

- (void)mouseExited:(NSEvent *)theEvent {
    self.mouseInside = NO;
}

static NSGradient *gradientWithTargetColor(NSColor *targetColor) {
    NSArray *colors = [NSArray arrayWithObjects:[targetColor colorWithAlphaComponent:0],
                       targetColor,
                       targetColor,
                       [targetColor colorWithAlphaComponent:0], nil];
    const CGFloat locations[4] = { 0.0, 0.35, 0.65, 1.0 };
    return [[NSGradient alloc] initWithColors:colors atLocations:locations colorSpace:[NSColorSpace sRGBColorSpace]];
}

- (void)drawBackgroundInRect:(NSRect)dirtyRect {
    // Custom background drawing. We don't call super at all.
    [self.backgroundColor set];
    // Fill with the background color first
    NSRectFill(self.bounds);

    // Draw a gradient
    if (self.mouseInside && self.highlightable) {
        NSRect selectionRect = NSRect(self.bounds);
        [[NSColor ringGreyHighlight] setFill];
        NSBezierPath *selectionPath = [NSBezierPath bezierPathWithRoundedRect:selectionRect xRadius:2 yRadius:2];
        [selectionPath fill];
    }
}

- (NSRect)separatorRect {
    NSRect separatorRect = self.bounds;
    separatorRect.origin.y = NSMaxY(separatorRect) - 1;
    separatorRect.size.height = 1;
    return separatorRect;
}

// Only called if the table is set with a horizontal grid
- (void)drawSeparatorInRect:(NSRect)dirtyRect {
    // Use a common shared method of drawing the separator
    DrawSeparatorInRect([self separatorRect]);
}

// Only called if the 'selected' property is yes.
- (void)drawSelectionInRect:(NSRect)dirtyRect {
    // Check the selectionHighlightStyle, in case it was set to None
    if (self.selectionHighlightStyle != NSTableViewSelectionHighlightStyleNone) {
        // We want a hard-crisp stroke, and stroking 1 pixel will border half on one side and half on another, so we offset by the 0.5 to handle this
        NSRect selectionRect = NSRect(self.bounds);
        [[NSColor ringGreyHighlight] setFill];
        NSBezierPath *selectionPath = [NSBezierPath bezierPathWithRoundedRect:selectionRect xRadius:2 yRadius:2];
        [selectionPath fill];
    }
}

// interiorBackgroundStyle is normaly "dark" when the selection is drawn (self.selected == YES) and we are in a key window (self.emphasized == YES). However, we always draw a light selection, so we override this method to always return a light color.
- (NSBackgroundStyle)interiorBackgroundStyle {
    return NSBackgroundStyleLight;
}

- (void)setFrame:(NSRect)frameRect {
    [super setFrame:frameRect];
    // We need to invalidate more things when live-resizing since we fill with a gradient and stroke
    if ([self inLiveResize]) {
        // Redraw everything if we are using a gradient
        if (self.selected || self.mouseInside) {
            [self setNeedsDisplay:YES];
        } else {
            // Redraw our horizontal grid line, which is a gradient
            [self setNeedsDisplayInRect:[self separatorRect]];
        }
    }
}

@end

void DrawSeparatorInRect(NSRect rect) {
    // Cache the gradient for performance
    static NSGradient *gradient = nil;
    if (gradient == nil) {
        gradient = gradientWithTargetColor([NSColor colorWithSRGBRed:.80 green:.80 blue:.80 alpha:1]);
    }
    [gradient drawInRect:rect angle:0];
}