macosx: Dynamically adjust the positioning of the library control buttons in VLCMainVideoView according to window titlebar

Signed-off-by: Claudio Cambra <developer@claudiocambra.com>

modules/gui/macosx/UI/VLCMainVideoView.xib

@@ -11,7 +11,10 @@
             <connections>
                 <outlet property="controlsBar" destination="3" id="Mfq-2w-2uR"/>
                 <outlet property="mainControlsView" destination="D4V-Zd-qvB" id="KwM-ya-ETn"/>
+                <outlet property="playlistButton" destination="Drq-if-dw4" id="BZe-Cr-mzZ"/>
+                <outlet property="playlistButtonTopConstraint" destination="VyM-t4-y6F" id="V94-GS-KcS"/>
                 <outlet property="returnButton" destination="UoQ-34-Pox" id="nyY-OF-9zj"/>
+                <outlet property="returnButtonTopConstraint" destination="0l2-eC-67c" id="78K-sz-kmV"/>
                 <outlet property="view" destination="WRu-Ic-lQK" id="B9p-x5-Kd8"/>
                 <outlet property="voutView" destination="mAS-4a-RS8" id="GeX-XO-HYC"/>
             </connections>

modules/gui/macosx/windows/video/VLCMainVideoViewController.h

@@ -34,6 +34,8 @@ NS_ASSUME_NONNULL_BEGIN
 @property (readwrite, strong) IBOutlet VLCControlsBarCommon *controlsBar;
 @property (readwrite, strong) IBOutlet NSButton *returnButton;
 @property (readwrite, strong) IBOutlet NSButton *playlistButton;
+@property (readwrite, strong) IBOutlet NSLayoutConstraint *returnButtonTopConstraint;
+@property (readwrite, strong) IBOutlet NSLayoutConstraint *playlistButtonTopConstraint;
 
 @property (readwrite, nonatomic) BOOL autohideControls;
 @property (readwrite, nonatomic) BOOL displayLibraryControls;

modules/gui/macosx/windows/video/VLCMainVideoViewController.m

@@ -23,6 +23,7 @@
 #import "VLCMainVideoViewController.h"
 
 #import "library/VLCLibraryWindow.h"
+#import "library/VLCLibraryUIUnits.h"
 
 #import "main/VLCMain.h"
 
@@ -53,6 +54,7 @@
 
     [self setDisplayLibraryControls:[self.view.window class] == [VLCLibraryWindow class]];
     [self updatePlaylistToggleState];
+    [self updateLibraryControlsTopConstraint];
 
     NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
     [notificationCenter addObserver:self
@@ -113,6 +115,7 @@
 {
     [self stopAutohideTimer];
     [self updatePlaylistToggleState];
+    [self updateLibraryControlsTopConstraint];
 
     if (!_mainControlsView.hidden && !_autohideControls) {
         return;
@@ -146,6 +149,28 @@
     }
 }
 
+- (void)updateLibraryControlsTopConstraint
+{
+    const NSWindow * const viewWindow = self.view.window;
+    const NSView * const titlebarView = [viewWindow standardWindowButton:NSWindowCloseButton].superview;
+    const CGFloat windowTitlebarHeight = titlebarView.frame.size.height;
+
+    const BOOL windowFullscreen = [(VLCWindow*)viewWindow isInNativeFullscreen] || [(VLCWindow*)viewWindow fullscreen];
+    const CGFloat spaceToTitlebar = viewWindow.titlebarAppearsTransparent ? [VLCLibraryUIUnits smallSpacing] : [VLCLibraryUIUnits mediumSpacing];
+    const CGFloat topSpaceWithTitlebar = windowTitlebarHeight + spaceToTitlebar;
+
+    // Since the close/maximise/minimise buttons go on the left, we want to make sure the return
+    // button does not overlap. But for the playlist button, as long as the toolbar and titlebar
+    // appears fully transparent, it looks nicer to leave it at the top
+    const CGFloat returnButtonTopSpace = titlebarView.hidden || windowFullscreen ?
+        [VLCLibraryUIUnits mediumSpacing] : topSpaceWithTitlebar;
+    const CGFloat playlistButtonTopSpace = viewWindow.toolbar.visible && viewWindow.titlebarAppearsTransparent && !windowFullscreen ?
+        topSpaceWithTitlebar : [VLCLibraryUIUnits mediumSpacing];
+
+    _returnButtonTopConstraint.constant = returnButtonTopSpace;
+    _playlistButtonTopConstraint.constant = playlistButtonTopSpace;
+}
+
 - (IBAction)togglePlaylist:(id)sender
 {
     VLCLibraryWindow *libraryWindow = (VLCLibraryWindow*)self.view.window;