1 files changed, 109 insertions, 0 deletions
diff --git a/Framework/MASShortcutValidator.m b/Framework/MASShortcutValidator.m
new file mode 100644
index 0000000..4fcba9b
--- /dev/null
+++ b/Framework/MASShortcutValidator.m
@@ -0,0 +1,109 @@
+#import "MASShortcutValidator.h"
+
+@implementation MASShortcutValidator
+
++ (instancetype) sharedValidator
+{
+    static dispatch_once_t once;
+    static MASShortcutValidator *sharedInstance;
+    dispatch_once(&once, ^{
+        sharedInstance = [[self alloc] init];
+    });
+    return sharedInstance;
+}
+
+- (BOOL) isShortcutValid: (MASShortcut*) shortcut
+{
+    NSUInteger keyCode = [shortcut keyCode];
+    NSUInteger modifiers = [shortcut modifierFlags];
+
+    // Allow any function key with any combination of modifiers
+    BOOL includesFunctionKey = ((keyCode == kVK_F1) || (keyCode == kVK_F2) || (keyCode == kVK_F3) || (keyCode == kVK_F4) ||
+                                (keyCode == kVK_F5) || (keyCode == kVK_F6) || (keyCode == kVK_F7) || (keyCode == kVK_F8) ||
+                                (keyCode == kVK_F9) || (keyCode == kVK_F10) || (keyCode == kVK_F11) || (keyCode == kVK_F12) ||
+                                (keyCode == kVK_F13) || (keyCode == kVK_F14) || (keyCode == kVK_F15) || (keyCode == kVK_F16) ||
+                                (keyCode == kVK_F17) || (keyCode == kVK_F18) || (keyCode == kVK_F19) || (keyCode == kVK_F20));
+    if (includesFunctionKey) return YES;
+
+    // Do not allow any other key without modifiers
+    BOOL hasModifierFlags = (modifiers > 0);
+    if (!hasModifierFlags) return NO;
+
+    // Allow any hotkey containing Control or Command modifier
+    BOOL includesCommand = ((modifiers & NSCommandKeyMask) > 0);
+    BOOL includesControl = ((modifiers & NSControlKeyMask) > 0);
+    if (includesCommand || includesControl) return YES;
+
+    // Allow Option key only in selected cases
+    BOOL includesOption = ((modifiers & NSAlternateKeyMask) > 0);
+    if (includesOption) {
+
+        // Always allow Option-Space and Option-Escape because they do not have any bind system commands
+        if ((keyCode == kVK_Space) || (keyCode == kVK_Escape)) return YES;
+
+        // Allow Option modifier with any key even if it will break the system binding
+        if (_allowAnyShortcutWithOptionModifier) return YES;
+    }
+
+    // The hotkey does not have any modifiers or violates system bindings
+    return NO;
+}
+
+- (BOOL) isShortcut: (MASShortcut*) shortcut alreadyTakenInMenu: (NSMenu*) menu explanation: (NSString**) explanation
+{
+    NSString *keyEquivalent = [shortcut keyCodeStringForKeyEquivalent];
+    NSUInteger flags = [shortcut modifierFlags];
+
+    for (NSMenuItem *menuItem in menu.itemArray) {
+        if (menuItem.hasSubmenu && [self isShortcut:shortcut alreadyTakenInMenu:[menuItem submenu] explanation:explanation]) return YES;
+        
+        BOOL equalFlags = (MASPickCocoaModifiers(menuItem.keyEquivalentModifierMask) == flags);
+        BOOL equalHotkeyLowercase = [menuItem.keyEquivalent.lowercaseString isEqualToString:keyEquivalent];
+        
+        // Check if the cases are different, we know ours is lower and that shift is included in our modifiers
+        // If theirs is capitol, we need to add shift to their modifiers
+        if (equalHotkeyLowercase && ![menuItem.keyEquivalent isEqualToString:keyEquivalent]) {
+            equalFlags = (MASPickCocoaModifiers(menuItem.keyEquivalentModifierMask | NSShiftKeyMask) == flags);
+        }
+        
+        if (equalFlags && equalHotkeyLowercase) {
+            if (explanation) {
+                *explanation = NSLocalizedString(@"This shortcut cannot be used because it is already used by the menu item ‘%@’.",
+                                                     @"Message for alert when shortcut is already used");
+                *explanation = [NSString stringWithFormat:*explanation, menuItem.title];
+            }
+            return YES;
+        }
+    }
+    return NO;
+}
+
+- (BOOL) isShortcutAlreadyTakenBySystem: (MASShortcut*) shortcut explanation: (NSString**) explanation
+{
+	CFArrayRef globalHotKeys;
+	if (CopySymbolicHotKeys(&globalHotKeys) == noErr) {
+
+        // Enumerate all global hotkeys and check if any of them matches current shortcut
+        for (CFIndex i = 0, count = CFArrayGetCount(globalHotKeys); i < count; i++) {
+            CFDictionaryRef hotKeyInfo = CFArrayGetValueAtIndex(globalHotKeys, i);
+            CFNumberRef code = CFDictionaryGetValue(hotKeyInfo, kHISymbolicHotKeyCode);
+            CFNumberRef flags = CFDictionaryGetValue(hotKeyInfo, kHISymbolicHotKeyModifiers);
+
+            if (([(__bridge NSNumber *)code unsignedIntegerValue] == [shortcut keyCode]) &&
+                ([(__bridge NSNumber *)flags unsignedIntegerValue] == [shortcut carbonFlags])) {
+
+                if (explanation) {
+                    *explanation = NSLocalizedString(@"This combination cannot be used because it is already used by a system-wide "
+                                                     @"keyboard shortcut.\nIf you really want to use this key combination, most shortcuts "
+                                                     @"can be changed in the Keyboard & Mouse panel in System Preferences.",
+                                                     @"Message for alert when shortcut is already used by the system");
+                }
+                return YES;
+            }
+        }
+        CFRelease(globalHotKeys);
+    }
+    return [self isShortcut:shortcut alreadyTakenInMenu:[NSApp mainMenu] explanation:explanation];
+}
+
+@end