Add initial iOS application

This is already in a working state, but is still missing a few things.
For example, there is no proper progress indication during generation
and the UI just hangs and there's no way to delete a site yet.

iOS/AddSiteController.m

@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2016, Jonathan Schleifer <js@heap.zone>
+ *
+ * https://heap.zone/git/?p=scrypt-pwgen.git
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+@import ObjFW_Bridge;
+
+#import "AddSiteController.h"
+
+static void
+showAlert(UIViewController *controller, NSString *title, NSString *message)
+{
+	UIAlertController *alert = [UIAlertController
+	    alertControllerWithTitle: title
+			     message: message
+		      preferredStyle: UIAlertControllerStyleAlert];
+	[alert addAction:
+	    [UIAlertAction actionWithTitle: @"OK"
+				     style: UIAlertActionStyleDefault
+				   handler: nil]];
+
+	[controller presentViewController: alert
+				 animated: YES
+			       completion: nil];
+}
+
+@implementation AddSiteController
+- (void)dealloc
+{
+	[_nameField release];
+	[_lengthField release];
+	[_legacySwitch release];
+	[_mainViewController release];
+
+	[super dealloc];
+}
+
+- (IBAction)done: (id)sender
+{
+	OFString *name = [self.nameField.text OFObject];
+	OFString *lengthStr = [self.lengthField.text OFObject];
+	bool lengthValid = true;
+	size_t length;
+
+	if ([name length] == 0) {
+		showAlert(self, @"Name missing", @"Please enter a name.");
+		return;
+	}
+
+	@try {
+		length = (size_t)[lengthStr decimalValue];
+
+		if (length < 3 || length > 64)
+			lengthValid = false;
+	} @catch (OFInvalidFormatException *e) {
+		lengthValid = false;
+	}
+
+	if (!lengthValid) {
+		showAlert(self, @"Invalid length",
+		    @"Please enter a number between 3 and 64.");
+		return;
+	}
+
+	if ([self.mainViewController.siteStorage hasSite: name]) {
+		showAlert(self, @"Site Already Exists",
+		    @"Please pick a name that does not exist yet.");
+		return;
+	}
+
+	[self.mainViewController.siteStorage
+	    setSite: name
+	     length: length
+	     legacy: self.legacySwitch.enabled];
+
+	[self.mainViewController.tableView reloadData];
+
+	[self.navigationController popViewControllerAnimated: YES];
+}
+
+- (IBAction)cancel: (id)sender
+{
+	[self.navigationController popViewControllerAnimated: YES];
+}
+@end