Merge pull request #1538 from ychin/mmtabs-rtl

MMTabline: Add right-to-left (RTL) locale support

Author: ychin

src/MacVim/MMAppController.m

@@ -174,8 +174,8 @@ + (void)registerDefaults
 
     NSDictionary *macvimDefaults = [NSDictionary dictionaryWithObjectsAndKeys:
         [NSNumber numberWithBool:NO],     MMNoWindowKey,
-        [NSNumber numberWithInt:120],     MMTabMinWidthKey,
-        [NSNumber numberWithInt:200],     MMTabOptimumWidthKey,
+        [NSNumber numberWithInt:130],     MMTabMinWidthKey,
+        [NSNumber numberWithInt:210],     MMTabOptimumWidthKey,
         [NSNumber numberWithBool:YES],    MMShowAddTabButtonKey,
         [NSNumber numberWithBool:NO],     MMShowTabScrollButtonsKey,
         [NSNumber numberWithInt:2],       MMTextInsetLeftKey,

src/MacVim/MMTabline/MMTabline.h

@@ -55,8 +55,8 @@
 - (void)selectTabAtIndex:(NSInteger)index;
 - (MMTab *)tabAtIndex:(NSInteger)index;
 - (void)scrollTabToVisibleAtIndex:(NSInteger)index;
-- (void)scrollLeftOneTab;
-- (void)scrollRightOneTab;
+- (void)scrollBackwardOneTab;
+- (void)scrollForwardOneTab;
 - (void)setTablineSelBackground:(NSColor *)back foreground:(NSColor *)fore;
 
 @end

src/MacVim/MMTabline/MMTabline.m

@@ -8,10 +8,10 @@
     CGFloat remainder;
 } TabWidth;
 
-const CGFloat OptimumTabWidth = 220;
-const CGFloat MinimumTabWidth = 100;
-const CGFloat TabOverlap      = 6;
-const CGFloat ScrollOneTabAllowance = 0.25; // If we are showing 75+% of the tab, consider it to be fully shown when deciding whether to scroll to next tab.
+static const CGFloat OptimumTabWidth = 200;
+static const CGFloat MinimumTabWidth = 100;
+static const CGFloat TabOverlap      = 6;
+static const CGFloat ScrollOneTabAllowance = 0.25; // If we are showing 75+% of the tab, consider it to be fully shown when deciding whether to scroll to next tab.
 
 static MMHoverButton* MakeHoverButton(MMTabline *tabline, MMHoverButtonImage imageType, NSString *tooltip, SEL action, BOOL continuous) {
     MMHoverButton *button = [MMHoverButton new];
@@ -44,8 +44,8 @@ @implementation MMTabline
     CGFloat _xOffsetForDrag;
     NSInteger _initialDraggedTabIndex;
     NSInteger _finalDraggedTabIndex;
-    MMHoverButton *_leftScrollButton;
-    MMHoverButton *_rightScrollButton;
+    MMHoverButton *_backwardScrollButton;
+    MMHoverButton *_forwardScrollButton;
     id _scrollWheelEventMonitor;
 }
 
@@ -82,23 +82,40 @@ - (instancetype)initWithFrame:(NSRect)frameRect
         _scrollView.documentView = _tabsContainer;
         [self addSubview:_scrollView];
 
-        _addTabButton = MakeHoverButton(self, MMHoverButtonImageAddTab, NSLocalizedString(@"create-new-tab-button", @"Create a new tab button"), @selector(addTabAtEnd), NO);
-        _leftScrollButton = MakeHoverButton(self, MMHoverButtonImageScrollLeft, NSLocalizedString(@"scroll-tabs-backward", @"Scroll backward button in tabs line"), @selector(scrollLeftOneTab), YES);
-        _rightScrollButton = MakeHoverButton(self, MMHoverButtonImageScrollRight, NSLocalizedString(@"scroll-tabs-forward", @"Scroll forward button in tabs line"), @selector(scrollRightOneTab), YES);
-
-        [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[_leftScrollButton][_rightScrollButton]-5-[_scrollView]-5-[_addTabButton]" options:NSLayoutFormatAlignAllCenterY metrics:nil views:NSDictionaryOfVariableBindings(_scrollView, _leftScrollButton, _rightScrollButton, _addTabButton)]];
+        _addTabButton = MakeHoverButton(
+                self,
+                MMHoverButtonImageAddTab,
+                NSLocalizedString(@"create-new-tab-button", @"Create a new tab button"),
+                @selector(addTabAtEnd),
+                NO);
+        _backwardScrollButton = MakeHoverButton(
+                self,
+                [self useRightToLeft] ? MMHoverButtonImageScrollRight : MMHoverButtonImageScrollLeft,
+                NSLocalizedString(@"scroll-tabs-backward", @"Scroll backward button in tabs line"),
+                @selector(scrollBackwardOneTab),
+                YES);
+        _forwardScrollButton = MakeHoverButton(
+                self,
+                [self useRightToLeft] ? MMHoverButtonImageScrollLeft : MMHoverButtonImageScrollRight,
+                NSLocalizedString(@"scroll-tabs-forward", @"Scroll forward button in tabs line"),
+                @selector(scrollForwardOneTab),
+                YES);
+
+        [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[_backwardScrollButton][_forwardScrollButton]-5-[_scrollView]-5-[_addTabButton]" options:NSLayoutFormatAlignAllCenterY metrics:nil views:NSDictionaryOfVariableBindings(_scrollView, _backwardScrollButton, _forwardScrollButton, _addTabButton)]];
         [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[_scrollView]|" options:0 metrics:nil views:@{@"_scrollView":_scrollView}]];
 
-        _tabScrollButtonsLeadingConstraint = [NSLayoutConstraint constraintWithItem:_leftScrollButton attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeLeading multiplier:1 constant:5];
+        _tabScrollButtonsLeadingConstraint = [NSLayoutConstraint constraintWithItem:_backwardScrollButton attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeLeading multiplier:1 constant:5];
         [self addConstraint:_tabScrollButtonsLeadingConstraint];
 
         _addTabButtonTrailingConstraint = [NSLayoutConstraint constraintWithItem:self attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:_addTabButton attribute:NSLayoutAttributeTrailing multiplier:1 constant:5];
         [self addConstraint:_addTabButtonTrailingConstraint];
 
         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didScroll:) name:NSViewBoundsDidChangeNotification object:_scrollView.contentView];
+        if ([self useRightToLeft]) {
+            [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateTabsContainerBoundsForRTL:) name:NSViewFrameDidChangeNotification object:_tabsContainer];
+        }
 
         [self addScrollWheelMonitor];
-
     }
     return self;
 }
@@ -194,7 +211,7 @@ - (void)setShowsTabScrollButtons:(BOOL)showsTabScrollButtons
     //   (see -drawRect: in MMTab.m).
     if (_showsTabScrollButtons != showsTabScrollButtons) {
         _showsTabScrollButtons = showsTabScrollButtons;
-        _tabScrollButtonsLeadingConstraint.constant = showsTabScrollButtons ? 5 : -((NSWidth(_leftScrollButton.frame) * 2) + 5 + MMTabShadowBlurRadius);
+        _tabScrollButtonsLeadingConstraint.constant = showsTabScrollButtons ? 5 : -((NSWidth(_backwardScrollButton.frame) * 2) + 5 + MMTabShadowBlurRadius);
     }
 }
 
@@ -244,8 +261,8 @@ - (void)setTablineSelFgColor:(NSColor *)color
 {
     _tablineSelFgColor = color;
     _addTabButton.fgColor = color;
-    _leftScrollButton.fgColor = color;
-    _rightScrollButton.fgColor = color;
+    _backwardScrollButton.fgColor = color;
+    _forwardScrollButton.fgColor = color;
     for (MMTab *tab in _tabs) tab.state = tab.state;
 }
 
@@ -280,6 +297,7 @@ - (NSInteger)addTabAtIndex:(NSInteger)index
     NSRect frame      = _tabsContainer.bounds;
     frame.size.width  = index == _tabs.count ? t.width + t.remainder : t.width;
     frame.origin.x    = index * (t.width - TabOverlap);
+    frame = [self flipRectRTL:frame];
     MMTab *newTab = [[MMTab alloc] initWithFrame:frame tabline:self];
 
     [_tabs insertObject:newTab atIndex:index];
@@ -383,6 +401,7 @@ - (void)updateTabsByTags:(NSInteger *)tags len:(NSUInteger)len delayTabResize:(B
             NSRect frame      = _tabsContainer.bounds;
             frame.size.width  = i == (len - 1) ? t.width + t.remainder : t.width;
             frame.origin.x    = i * (t.width - TabOverlap);
+            frame = [self flipRectRTL:frame];
             MMTab *newTab = [[MMTab alloc] initWithFrame:frame tabline:self];
             newTab.tag = tag;
             [newTabs addObject:newTab];
@@ -533,19 +552,35 @@ - (void)setTablineSelBackground:(NSColor *)back foreground:(NSColor *)fore
 
 #pragma mark - Helpers
 
-NSComparisonResult SortTabsForZOrder(MMTab *tab1, MMTab *tab2, void *draggedTab)
+NSComparisonResult SortTabsForZOrder(MMTab *tab1, MMTab *tab2, void *draggedTab, BOOL rtl)
 {   // Z-order, highest to lowest: dragged, selected, hovered, rightmost
     if (tab1 == (__bridge MMTab *)draggedTab) return NSOrderedDescending;
     if (tab2 == (__bridge MMTab *)draggedTab) return NSOrderedAscending;
     if (tab1.state == MMTabStateSelected) return NSOrderedDescending;
     if (tab2.state == MMTabStateSelected) return NSOrderedAscending;
     if (tab1.state == MMTabStateUnselectedHover) return NSOrderedDescending;
     if (tab2.state == MMTabStateUnselectedHover) return NSOrderedAscending;
-    if (NSMinX(tab1.frame) < NSMinX(tab2.frame)) return NSOrderedAscending;
-    if (NSMinX(tab1.frame) > NSMinX(tab2.frame)) return NSOrderedDescending;
+    if (rtl) {
+        if (NSMinX(tab1.frame) > NSMinX(tab2.frame)) return NSOrderedAscending;
+        if (NSMinX(tab1.frame) < NSMinX(tab2.frame)) return NSOrderedDescending;
+    } else {
+        if (NSMinX(tab1.frame) < NSMinX(tab2.frame)) return NSOrderedAscending;
+        if (NSMinX(tab1.frame) > NSMinX(tab2.frame)) return NSOrderedDescending;
+    }
     return NSOrderedSame;
 }
 
+NSComparisonResult SortTabsForZOrderLTR(MMTab *tab1, MMTab *tab2, void *draggedTab)
+{
+    return SortTabsForZOrder(tab1, tab2, draggedTab, NO);
+}
+
+
+NSComparisonResult SortTabsForZOrderRTL(MMTab *tab1, MMTab *tab2, void *draggedTab)
+{
+    return SortTabsForZOrder(tab1, tab2, draggedTab, YES);
+}
+
 - (TabWidth)tabWidthForTabs:(NSInteger)numTabs
 {
     // Each tab (except the first) overlaps the previous tab by TabOverlap
@@ -620,9 +655,17 @@ - (void)fixupCloseButtons
 
 - (void)fixupTabZOrder
 {
-    [_tabsContainer sortSubviewsUsingFunction:SortTabsForZOrder context:(__bridge void *)(_draggedTab)];
+    if ([self useRightToLeft]) {
+        [_tabsContainer sortSubviewsUsingFunction:SortTabsForZOrderRTL
+                                          context:(__bridge void *)(_draggedTab)];
+    } else {
+        [_tabsContainer sortSubviewsUsingFunction:SortTabsForZOrderLTR
+                                          context:(__bridge void *)(_draggedTab)];
+    }
 }
 
+/// The main layout function that calculates the tab positions and animate them
+/// accordingly. Call this every time tabs have been added/removed/moved.
 - (void)fixupLayoutWithAnimation:(BOOL)shouldAnimate delayResize:(BOOL)delayResize
 {
     if (!self.useAnimation)
@@ -656,6 +699,7 @@ - (void)fixupLayoutWithAnimation:(BOOL)shouldAnimate delayResize:(BOOL)delayResi
             frame.size.width = i == _tabs.count - 1 ? t.width + t.remainder : t.width;
             frame.origin.x = i != 0 ? i * (t.width - TabOverlap) : 0;
         }
+        frame = [self flipRectRTL:frame];
         if (shouldAnimate) {
             [NSAnimationContext runAnimationGroup:^(NSAnimationContext * _Nonnull context) {
                 context.allowsImplicitAnimation = YES;
@@ -673,8 +717,20 @@ - (void)fixupLayoutWithAnimation:(BOOL)shouldAnimate delayResize:(BOOL)delayResi
         NSRect frame = _tabsContainer.frame;
         frame.size.width = t.width * _tabs.count - TabOverlap * (_tabs.count - 1);
         frame.size.width = NSWidth(frame) < NSWidth(_scrollView.frame) ? NSWidth(_scrollView.frame) : NSWidth(frame);
-        if (shouldAnimate) _tabsContainer.animator.frame = frame;
-        else _tabsContainer.frame = frame;
+        const BOOL sizeDecreasing = NSWidth(frame) < NSWidth(_tabsContainer.frame);
+        if ([self useRightToLeft]) {
+            // In RTL mode we flip the X coords and grow from 0 to negative.
+            // See updateTabsContainerBoundsForRTL which auto-updates the
+            // bounds to match the frame.
+            frame.origin.x = -NSWidth(frame);
+        }
+        if (shouldAnimate && sizeDecreasing) {
+            // Need to animate to make sure we don't immediately get clamped by
+            // the new size if we are already scrolled all the way to the back.
+            _tabsContainer.animator.frame = frame;
+        } else {
+            _tabsContainer.frame = frame;
+        }
         [self updateTabScrollButtonsEnabledState];
     }
 }
@@ -684,6 +740,41 @@ - (void)fixupLayoutWithAnimation:(BOOL)shouldAnimate
     [self fixupLayoutWithAnimation:shouldAnimate delayResize:NO];
 }
 
+#pragma mark - Right-to-left (RTL) support
+
+- (BOOL)useRightToLeft
+{
+    // MMTabs support RTL locales. In such locales user interface items are
+    // laid out from right to left. The layout of hover buttons and views are
+    // automatically flipped by AppKit, but we need to handle this manually in
+    // the tab placement logic since that is custom logic.
+    return self.userInterfaceLayoutDirection == NSUserInterfaceLayoutDirectionRightToLeft;
+}
+
+- (void)updateTabsContainerBoundsForRTL:(NSNotification *)notification
+{
+    // In RTL mode, we grow the tabs container to the left. We want to preserve
+    // stability of the scroll view's bounds, and also have the tabs animate
+    // correctly. To do this, we have to make sure the container bounds matches
+    // the frame at all times. This "cancels out" the negative X offsets with
+    // each other and ease calculations.
+    // E.g. an MMTab with origin (-100,0) inside the _tabsContainer coordinate
+    // space will actually be (-100,0) in the scroll view as well.
+    // In LTR mode we don't need this, since _tabsContainer's origin is always
+    // at (0,0).
+    _tabsContainer.bounds = _tabsContainer.frame;
+}
+
+- (NSRect)flipRectRTL:(NSRect)frame
+{
+    if ([self useRightToLeft]) {
+        // In right-to-left mode, we flip the X coordinates for all the tabs so
+        // they start at 0 and grow in the negative direction.
+        frame.origin.x = -NSMaxX(frame);
+    }
+    return frame;
+}
+
 #pragma mark - Mouse
 
 - (void)updateTrackingAreas
@@ -796,9 +887,15 @@ - (void)mouseDragged:(NSEvent *)event
     [self fixupTabZOrder];
     [_draggedTab setFrameOrigin:NSMakePoint(mouse.x - _xOffsetForDrag, 0)];
     MMTab *selectedTab = _selectedTabIndex == -1 ? nil : _tabs[_selectedTabIndex];
+    const BOOL rightToLeft = [self useRightToLeft];
     [_tabs sortWithOptions:NSSortStable usingComparator:^NSComparisonResult(MMTab *t1, MMTab *t2) {
-        if (NSMinX(t1.frame) <= NSMinX(t2.frame)) return NSOrderedAscending;
-        if (NSMinX(t1.frame) >  NSMinX(t2.frame)) return NSOrderedDescending;
+        if (rightToLeft) {
+            if (NSMaxX(t1.frame) >= NSMaxX(t2.frame)) return NSOrderedAscending;
+            if (NSMaxX(t1.frame) <  NSMaxX(t2.frame)) return NSOrderedDescending;
+        } else {
+            if (NSMinX(t1.frame) <= NSMinX(t2.frame)) return NSOrderedAscending;
+            if (NSMinX(t1.frame) >  NSMinX(t2.frame)) return NSOrderedDescending;
+        }
         return NSOrderedSame;
     }];
     _selectedTabIndex = _selectedTabIndex == -1 ? -1 : [_tabs indexOfObject:selectedTab];
@@ -820,11 +917,18 @@ - (void)updateTabScrollButtonsEnabledState
     // on either side of _scrollView.
     NSRect clipBounds = _scrollView.contentView.bounds;
     if (NSWidth(_tabsContainer.frame) <= NSWidth(clipBounds)) {
-        _leftScrollButton.enabled = NO;
-        _rightScrollButton.enabled = NO;
+        _backwardScrollButton.enabled = NO;
+        _forwardScrollButton.enabled = NO;
     } else {
-        _leftScrollButton.enabled  = clipBounds.origin.x > 0;
-        _rightScrollButton.enabled = clipBounds.origin.x + NSWidth(clipBounds) < NSMaxX(_tabsContainer.frame);
+        BOOL scrollLeftEnabled = NSMinX(clipBounds) > NSMinX(_tabsContainer.frame);
+        BOOL scrollRightEnabled = NSMaxX(clipBounds) < NSMaxX(_tabsContainer.frame);
+        if ([self useRightToLeft]) {
+            _backwardScrollButton.enabled = scrollRightEnabled;
+            _forwardScrollButton.enabled = scrollLeftEnabled;
+        } else {
+            _backwardScrollButton.enabled = scrollLeftEnabled;
+            _forwardScrollButton.enabled = scrollRightEnabled;
+        }
     }
 }
 
@@ -874,29 +978,37 @@ - (void)scrollTabToVisibleAtIndex:(NSInteger)index
     }
 }
 
-- (void)scrollLeftOneTab
+- (void)scrollBackwardOneTab
 {
     NSRect clipBounds = _scrollView.contentView.animator.bounds;
     for (NSInteger i = _tabs.count - 1; i >= 0; i--) {
         NSRect tabFrame = _tabs[i].frame;
         if (!NSContainsRect(clipBounds, tabFrame)) {
-            CGFloat allowance = i == 0 ? 0 : NSWidth(tabFrame) * ScrollOneTabAllowance;
-            if (NSMinX(tabFrame) + allowance < NSMinX(clipBounds)) {
+            const CGFloat allowance = (i == 0) ?
+                0 : NSWidth(tabFrame) * ScrollOneTabAllowance;
+            const BOOL outOfBounds = [self useRightToLeft] ?
+                NSMaxX(tabFrame) - allowance > NSMaxX(clipBounds) :
+                NSMinX(tabFrame) + allowance < NSMinX(clipBounds);
+            if (outOfBounds) {
                 [self scrollTabToVisibleAtIndex:i];
                 break;
             }
         }
     }
 }
 
-- (void)scrollRightOneTab
+- (void)scrollForwardOneTab
 {
     NSRect clipBounds = _scrollView.contentView.animator.bounds;
     for (NSInteger i = 0; i < _tabs.count; i++) {
         NSRect tabFrame = _tabs[i].frame;
         if (!NSContainsRect(clipBounds, tabFrame)) {
-            CGFloat allowance = i == _tabs.count - 1 ? 0 : NSWidth(tabFrame) * ScrollOneTabAllowance;
-            if (NSMaxX(tabFrame) - allowance > NSMaxX(clipBounds)) {
+            const CGFloat allowance = (i == _tabs.count - 1) ?
+                0 : NSWidth(tabFrame) * ScrollOneTabAllowance;
+            const BOOL outOfBounds = [self useRightToLeft] ?
+                NSMinX(tabFrame) + allowance < NSMinX(clipBounds) :
+                NSMaxX(tabFrame) - allowance > NSMaxX(clipBounds);
+            if (outOfBounds) {
                 [self scrollTabToVisibleAtIndex:i];
                 break;
             }

src/MacVim/MMVimView.m

@@ -264,12 +264,12 @@ - (IBAction)scrollToCurrentTab:(id)sender
 
 - (IBAction)scrollBackwardOneTab:(id)sender
 {
-    [tabline scrollLeftOneTab];
+    [tabline scrollBackwardOneTab];
 }
 
 - (IBAction)scrollForwardOneTab:(id)sender
 {
-    [tabline scrollRightOneTab];
+    [tabline scrollForwardOneTab];
 }
 
 - (void)showTabline:(BOOL)on