UI/AppKit: Add a Launch Client button to the DevTools banner

Extend the shared info bar with an action button that launches the
application-owned Firefox client. Report discovery or startup errors
through the existing error dialog.

Author: trflynn89

UI/AppKit/Application/ApplicationDelegate.mm

@@ -181,11 +181,16 @@ - (void)onDevtoolsEnabled
     auto message = MUST(String::formatted("DevTools is enabled on port {}", WebView::Application::browser_options().devtools_port));
 
     [self.info_bar showWithMessage:Ladybird::string_to_ns_string(message)
-                dismissButtonTitle:@"Disable"
-              dismissButtonClicked:^{
-                  MUST(WebView::Application::the().toggle_devtools_enabled());
-              }
-                         activeTab:self.active_tab];
+        actionButtonTitle:@"Launch Client"
+        actionButtonClicked:^{
+            if (auto result = WebView::Application::the().launch_devtools_client(); result.is_error())
+                WebView::Application::the().display_error_dialog(MUST(String::formatted("Unable to launch the DevTools client: {}", result.error())));
+        }
+        dismissButtonTitle:@"Disable"
+        dismissButtonClicked:^{
+            MUST(WebView::Application::the().toggle_devtools_enabled());
+        }
+        activeTab:self.active_tab];
 }
 
 - (void)onDevtoolsDisabled

UI/AppKit/Interface/InfoBar.h

@@ -10,13 +10,15 @@
 
 @class Tab;
 
-using InfoBarDismissed = void (^)(void);
+using InfoBarButtonClicked = void (^)(void);
 
 @interface InfoBar : NSStackView
 
 - (void)showWithMessage:(NSString*)message
+       actionButtonTitle:(NSString*)action_title
+     actionButtonClicked:(InfoBarButtonClicked)on_action
       dismissButtonTitle:(NSString*)title
-    dismissButtonClicked:(InfoBarDismissed)on_dismissed
+    dismissButtonClicked:(InfoBarButtonClicked)on_dismissed
                activeTab:(Tab*)tab;
 - (void)hide;
 

UI/AppKit/Interface/InfoBar.mm

@@ -16,8 +16,10 @@
 @interface InfoBar ()
 
 @property (nonatomic, strong) NSTextField* text_label;
+@property (nonatomic, strong) NSButton* action_button;
 @property (nonatomic, strong) NSButton* dismiss_button;
-@property (nonatomic, copy) InfoBarDismissed on_dismissed;
+@property (nonatomic, copy) InfoBarButtonClicked on_action;
+@property (nonatomic, copy) InfoBarButtonClicked on_dismissed;
 
 @end
 
@@ -28,12 +30,18 @@ - (instancetype)init
     if (self = [super init]) {
         self.text_label = [NSTextField labelWithString:@""];
 
+        self.action_button = [NSButton buttonWithTitle:@""
+                                                target:self
+                                                action:@selector(performAction:)];
+        [self.action_button setBezelStyle:NSBezelStyleAccessoryBarAction];
+
         self.dismiss_button = [NSButton buttonWithTitle:@""
                                                  target:self
                                                  action:@selector(dismiss:)];
         [self.dismiss_button setBezelStyle:NSBezelStyleAccessoryBarAction];
 
         [self addView:self.text_label inGravity:NSStackViewGravityLeading];
+        [self addView:self.action_button inGravity:NSStackViewGravityTrailing];
         [self addView:self.dismiss_button inGravity:NSStackViewGravityTrailing];
 
         [self setOrientation:NSUserInterfaceLayoutOrientationHorizontal];
@@ -46,12 +54,16 @@ - (instancetype)init
 }
 
 - (void)showWithMessage:(NSString*)message
+       actionButtonTitle:(NSString*)action_title
+     actionButtonClicked:(InfoBarButtonClicked)on_action
       dismissButtonTitle:(NSString*)title
-    dismissButtonClicked:(InfoBarDismissed)on_dismissed
+    dismissButtonClicked:(InfoBarButtonClicked)on_dismissed
                activeTab:(Tab*)tab
 {
     [self.text_label setStringValue:message];
 
+    self.action_button.title = action_title;
+    self.on_action = on_action;
     self.dismiss_button.title = title;
     self.on_dismissed = on_dismissed;
 
@@ -62,6 +74,12 @@ - (void)showWithMessage:(NSString*)message
     [self setHidden:NO];
 }
 
+- (void)performAction:(id)sender
+{
+    if (self.on_action)
+        self.on_action();
+}
+
 - (void)dismiss:(id)sender
 {
     if (self.on_dismissed) {