Refactor file-launching method in cmd

Previously the cmd util uses different strategies to open files based
on whether MacDown is currently running. This results in various
problems, the most prominent being that NSWorkspace cannot be used
to pass a path for files that do not exist.

This change unifies the opening strategy to always be based on
cross-application NSUserDefaults instead, and moves the open file
check from during application launch to application activation.
This makes the implementation simpler, and also solves the problem
aforementioned.

Fix #672.

MacDown/Code/Application/MPMainController.m

@@ -147,7 +147,6 @@ - (instancetype)init
                    name:MPDidDetectFreshInstallationNotification
                  object:self.prefereces];
     [self copyFiles];
-    [self openPendingFiles];
     return self;
 }
 
@@ -159,6 +158,11 @@ - (BOOL)applicationShouldOpenUntitledFile:(NSApplication *)sender
     return !self.prefereces.supressesUntitledDocumentOnLaunch;
 }
 
+- (void)applicationDidBecomeActive:(NSNotification *)notification
+{
+    [self openPendingFiles];
+}
+
 
 #pragma mark - SUUpdaterDelegate
 
@@ -214,7 +218,7 @@ - (void)openPendingFiles
     NSDocumentController *c = [NSDocumentController sharedDocumentController];
 
     NSUserDefaults *defaults = [[NSUserDefaults alloc] init];
-    NSArray *paths = [defaults objectForKey:@"filesToOpenOnNextLaunch"
+    NSArray *paths = [defaults objectForKey:kMPFilesToOpenKey
                                inSuiteNamed:kMPApplicationSuiteName];
 
     for (NSString *path in paths)
@@ -231,7 +235,7 @@ - (void)openPendingFiles
         }
     }
 
-    [defaults setObject:@[] forKey:@"filesToOpenOnNextLaunch"
+    [defaults setObject:@[] forKey:kMPFilesToOpenKey
            inSuiteNamed:kMPApplicationSuiteName];
     [defaults synchronize];
     treat();

MacDown/Code/Utility/MPGlobals.h

@@ -16,3 +16,5 @@ static NSString * const kMPCommandName = @"macdown";
 
 static NSString * const kMPHelpKey = @"help";
 static NSString * const kMPVersionKey = @"version";
+
+static NSString * const kMPFilesToOpenKey = @"filesToOpenOnNextLaunch";

macdown-cmd/main.m

@@ -23,24 +23,15 @@
     return runningInstances.firstObject;
 }
 
-
-void MPCollectForRunningMacDown(NSOrderedSet<NSURL *> *urls)
-{
-    NSWorkspace *workspace = [NSWorkspace sharedWorkspace];
-    for (NSURL *url in urls)
-        [workspace openFile:url.path withApplication:kMPApplicationName];
-}
-
-
-void MPCollectForUnlaunchedMacDown(NSOrderedSet<NSURL *> *urls)
+void MPCollectForMacDown(NSOrderedSet<NSURL *> *urls)
 {
     NSUserDefaults *defaults =
         [[NSUserDefaults alloc] initWithSuiteNamed:kMPApplicationSuiteName];
     NSMutableArray<NSString *> *urlStrings =
         [[NSMutableArray alloc] initWithCapacity:urls.count];
     for (NSURL *url in urls)
         [urlStrings addObject:url.path];
-    [defaults setObject:urlStrings forKey:@"filesToOpenOnNextLaunch"
+    [defaults setObject:urlStrings forKey:kMPFilesToOpenKey
            inSuiteNamed:kMPApplicationSuiteName];
     [defaults synchronize];
 }
@@ -70,15 +61,7 @@ int main(int argc, const char * argv[])
             NSURL *url = [NSURL URLWithString:escaped relativeToURL:pwdUrl];
             [urls addObject:url];
         }
-
-        // If the application is running, open all files with the first running
-        // instance. Otherwise save the file URLs, and start the app (saved URLs
-        // will be opened when the app launches).
-        NSRunningApplication *instance = MPRunningMacDownInstance();
-        if (instance)
-            MPCollectForRunningMacDown(urls);
-        else
-            MPCollectForUnlaunchedMacDown(urls);
+        MPCollectForMacDown(urls);
 
         // Launch MacDown.
         [[NSWorkspace sharedWorkspace] launchApplication:kMPApplicationName];