Add command line completion to :macaction command

This enables the user to cycle through all actions by typing
":maca <Tab>" and then repeatedly hitting <Tab>.  The help on :maca was
also updated.

(Initial patch by Nico Weber with some changes by Bjorn Winckler.)

runtime/doc/gui_mac.txt

@@ -341,16 +341,16 @@ to "~/.gvimrc": >
 <
 						*:maca* *:macaction*
 It is typical for menu items in Cocoa applications to bind to Objective-C
-selectors.  To support this, MacVim introduces the ":macaction" command.  This
+selectors.  To support this, MacVim introduces the |:macaction| command.  This
 command takes the name of an action message as its only parameter.  (An action
 message is an Objective-C message with "void" return type and a single
 parameter of type "id".)  For example, the "New Window" menu item on the
 "File" menu is created in the following manner: >
 	:an 10.290 File.New\ Window :macaction newWindow:<CR>
 
-Note 1: A menu item which is bound to ":macaction" will automatically be bound
+Note 1: A menu item which is bound to |:macaction| will automatically be bound
 to that action in all modes (as if ":an" was used).  It is not possible to
-bind to ":macaction" in one mode only.
+bind to |:macaction| in one mode only.
 Note 2: The action is "nil-targeted", which means it is passed down the first
 responder chain.
 
@@ -361,8 +361,11 @@ application bundle) which contains all actions that may be called.  The key in
 this dictionary is the name of the action message (case sensitive), the value
 is not used.
 
+Note: The |:macaction| command supports tab-completion so to cycle through
+all available commands type ":maca<Space><Tab>" and keep pressing <Tab>.
+
 Here is a random assortment of actions from Actions.plist which might be
-useful.
+useful.  
 
 Action				Description ~
 findNext:			Search forward using the "Find Pasteboard"

src/MacVim/MMBackend.h

@@ -24,6 +24,7 @@
     id                  frontendProxy;
     NSDictionary        *colorDict;
     NSDictionary        *sysColorDict;
+    NSDictionary        *actionDict;
     BOOL                inputReceived;
     BOOL                tabBarVisible;
     unsigned            backgroundColor;
@@ -54,6 +55,7 @@
 - (void)setSpecialColor:(int)color;
 - (void)setDefaultColorsBackground:(int)bg foreground:(int)fg;
 - (NSConnection *)connection;
+- (NSDictionary *)actionDict;
 
 - (BOOL)checkin;
 - (BOOL)openVimWindow;

src/MacVim/MMBackend.m

@@ -142,8 +142,12 @@ static NSString *MMSymlinkWarningString =
         sysColorDict = [[NSDictionary dictionaryWithContentsOfFile:path]
             retain];
 
-    if (!(colorDict && sysColorDict))
-        NSLog(@"ERROR: Failed to load color dictionaries.%@",
+    path = [mainBundle pathForResource:@"Actions" ofType:@"plist"];
+    if (path)
+        actionDict = [[NSDictionary dictionaryWithContentsOfFile:path] retain];
+
+    if (!(colorDict && sysColorDict && actionDict))
+        NSLog(@"ERROR: Failed to load dictionaries.%@",
                 MMSymlinkWarningString);
 
     return self;
@@ -215,6 +219,11 @@ static NSString *MMSymlinkWarningString =
     return connection;
 }
 
+- (NSDictionary *)actionDict
+{
+    return actionDict;
+}
+
 - (BOOL)checkin
 {
     if (![self connection]) {

src/MacVim/gui_macvim.m

@@ -1478,22 +1478,8 @@ gui_mch_toggle_tearoffs(int enable)
     static BOOL
 gui_macvim_is_valid_action(NSString *action)
 {
-    static NSDictionary *actionDict = nil;
-
-    if (!actionDict) {
-        NSBundle *mainBundle = [NSBundle mainBundle];
-        NSString *path = [mainBundle pathForResource:@"Actions"
-                                              ofType:@"plist"];
-        if (path) {
-            actionDict = [[NSDictionary alloc] initWithContentsOfFile:path];
-        } else {
-            // Allocate bogus dictionary so that error only pops up once.
-            actionDict = [NSDictionary new];
-            EMSG(_("E???: Failed to load action dictionary"));
-        }
-    }
-
-    return [actionDict objectForKey:action] != nil;
+    NSDictionary *actionDict = [[MMBackend sharedInstance] actionDict];
+    return actionDict && [actionDict objectForKey:action] != nil;
 }
 
 
@@ -1834,3 +1820,35 @@ odb_end(void)
 }
 
 #endif // FEAT_ODB_EDITOR
+
+
+    char_u *
+get_macaction_name(expand_T *xp, int idx)
+{
+    static char_u *str = NULL;
+    NSDictionary *actionDict = [[MMBackend sharedInstance] actionDict];
+
+    if (nil == actionDict || idx < 0 || idx >= [actionDict count])
+        return NULL;
+
+    NSString *string = [[actionDict allKeys] objectAtIndex:idx];
+    if (!string)
+        return NULL;
+
+    char_u *plainStr = (char_u*)[string UTF8String];
+
+#ifdef FEAT_MBYTE
+    if (str) {
+        vim_free(str);
+        str = NULL;
+    }
+    if (input_conv.vc_type != CONV_NONE) {
+        int len = [string lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
+        str = string_convert(&input_conv, plainStr, &len);
+        plainStr = str;
+    }
+#endif
+
+    return plainStr;
+}
+

src/ex_docmd.c

@@ -3792,6 +3792,14 @@ set_one_cmd_context(xp, buff)
 	    break;
 #endif
 
+#ifdef FEAT_GUI_MACVIM
+	case CMD_macaction:
+	    xp->xp_context = EXPAND_MACACTION;
+	    xp->xp_pattern = arg;
+	    break;
+#endif
+
+
 #endif /* FEAT_CMDL_COMPL */
 
 	default:

src/ex_getln.c

@@ -4449,6 +4449,9 @@ ExpandFromContext(xp, pat, num_file, file, options)
 	    {EXPAND_LANGUAGE, get_lang_arg, TRUE},
 #endif
 	    {EXPAND_ENV_VARS, get_env_name, TRUE},
+#ifdef FEAT_GUI_MACVIM
+	    {EXPAND_MACACTION, get_macaction_name, FALSE},
+#endif
 	};
 	int	i;
 

src/proto/gui_macvim.pro

@@ -201,3 +201,4 @@ OSErr odb_buffer_close(buf_T *buf);
 OSErr odb_post_buffer_write(buf_T *buf);
 void odb_end(void);
 
+char_u *get_macaction_name(expand_T *xp, int idx);

src/vim.h

@@ -689,6 +689,7 @@ extern char *(*dyn_libintl_textdomain)(const char *domainname);
 #define EXPAND_USER_DEFINED	30
 #define EXPAND_USER_LIST	31
 #define EXPAND_SHELLCMD		32
+#define EXPAND_MACACTION	33
 
 /* Values for exmode_active (0 is no exmode) */
 #define EXMODE_NORMAL		1