From 3c459ed7dfefe90fa0e69b3825094fb5d39aaf8b Mon Sep 17 00:00:00 2001
From: Sami Samhuri <sami@samhuri.net>
Date: Sun, 3 May 2015 20:25:40 -0700
Subject: [PATCH] improve state restoration, leverage restoration IDs more

---
 Blog/AppDelegate.m              |  9 ++++++---
 Blog/Base.lproj/Main.storyboard | 14 +++++++-------
 Blog/EditorViewController.m     |  3 ---
 Blog/PostsViewController.m      |  3 ---
 Blog/PreviewViewController.m    | 34 +++++++++------------------------
 5 files changed, 22 insertions(+), 41 deletions(-)

diff --git a/Blog/AppDelegate.m b/Blog/AppDelegate.m
index 7136cb9..3a10dec 100644
--- a/Blog/AppDelegate.m
+++ b/Blog/AppDelegate.m
@@ -72,9 +72,12 @@
 - (EditorViewController *)editorViewController {
     UISplitViewController *splitViewController = (UISplitViewController *)self.window.rootViewController;
     UINavigationController *navigationController = splitViewController.viewControllers.firstObject;
-    navigationController = navigationController.viewControllers.lastObject;
-    EditorViewController *editorViewController = (EditorViewController *)navigationController.viewControllers.firstObject;
-    return editorViewController;
+    if (navigationController.viewControllers.count > 1) {
+        navigationController = navigationController.viewControllers.lastObject;
+        EditorViewController *editorViewController = (EditorViewController *)navigationController.viewControllers.firstObject;
+        return editorViewController;
+    }
+    return nil;
 }
 
 - (ModelStore *)newModelStoreWithPath:(NSString *)dbPath {
diff --git a/Blog/Base.lproj/Main.storyboard b/Blog/Base.lproj/Main.storyboard
index 9153356..08bb683 100644
--- a/Blog/Base.lproj/Main.storyboard
+++ b/Blog/Base.lproj/Main.storyboard
@@ -73,7 +73,7 @@
                                             <constraint firstAttribute="width" secondItem="VV9-18-i5M" secondAttribute="height" multiplier="1:1" id="vkJ-Ki-XVe"/>
                                         </constraints>
                                     </imageView>
-                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="left" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="ydf-ii-P8M">
+                                    <button opaque="NO" contentMode="scaleToFill" restorationIdentifier="Link Button" contentHorizontalAlignment="left" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="ydf-ii-P8M">
                                         <rect key="frame" x="32" y="1" width="116" height="29"/>
                                         <fontDescription key="fontDescription" type="system" pointSize="14"/>
                                         <state key="normal" title="http://samhuri.net">
@@ -84,7 +84,7 @@
                                             <action selector="tappedLinkButton:" destination="JEX-9P-axG" eventType="touchUpInside" id="2Wx-9Z-i8K"/>
                                         </connections>
                                     </button>
-                                    <button opaque="NO" contentMode="scaleAspectFit" contentHorizontalAlignment="center" contentVerticalAlignment="center" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="81X-Pe-PFV">
+                                    <button opaque="NO" contentMode="scaleAspectFit" restorationIdentifier="Remove Link Button" contentHorizontalAlignment="center" contentVerticalAlignment="center" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="81X-Pe-PFV">
                                         <rect key="frame" x="565" y="0.0" width="30" height="30"/>
                                         <constraints>
                                             <constraint firstAttribute="width" secondItem="81X-Pe-PFV" secondAttribute="height" multiplier="1:1" id="iW2-b5-VdB"/>
@@ -117,7 +117,7 @@
                                     </mask>
                                 </variation>
                             </view>
-                            <textView clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="scaleToFill" alwaysBounceVertical="YES" translatesAutoresizingMaskIntoConstraints="NO" id="wrG-1y-ZY3">
+                            <textView clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="scaleToFill" restorationIdentifier="Editor Text View" alwaysBounceVertical="YES" translatesAutoresizingMaskIntoConstraints="NO" id="wrG-1y-ZY3">
                                 <rect key="frame" x="0.0" y="30" width="600" height="462"/>
                                 <color key="backgroundColor" red="0.26666666666666666" green="0.26666666666666666" blue="0.26666666666666666" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                                 <string key="text">The latest technology I've been learning is Palm's SDK for webOS,
@@ -210,7 +210,7 @@ wanted with as little input and thought as possible.</string>
                         <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
-                            <textField opaque="NO" clipsSubviews="YES" contentMode="scaleToFill" contentHorizontalAlignment="left" contentVerticalAlignment="center" borderStyle="roundedRect" textAlignment="center" minimumFontSize="17" translatesAutoresizingMaskIntoConstraints="NO" id="G2v-XU-V16">
+                            <textField opaque="NO" clipsSubviews="YES" contentMode="scaleToFill" restorationIdentifier="Text Field" contentHorizontalAlignment="left" contentVerticalAlignment="center" borderStyle="roundedRect" textAlignment="center" minimumFontSize="17" translatesAutoresizingMaskIntoConstraints="NO" id="G2v-XU-V16">
                                 <rect key="frame" x="16" y="285" width="568" height="30"/>
                                 <color key="backgroundColor" red="0.2666666667" green="0.2666666667" blue="0.2666666667" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                                 <color key="textColor" red="0.96862745100000003" green="0.96862745100000003" blue="0.96862745100000003" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
@@ -247,11 +247,11 @@ wanted with as little input and thought as possible.</string>
                         <rect key="frame" x="0.0" y="0.0" width="600" height="536"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
-                            <webView contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="0n2-Ma-NtP">
+                            <webView contentMode="scaleToFill" restorationIdentifier="Web View" translatesAutoresizingMaskIntoConstraints="NO" id="0n2-Ma-NtP">
                                 <rect key="frame" x="0.0" y="0.0" width="600" height="536"/>
                                 <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                 <connections>
-                                    <outlet property="delegate" destination="ixd-IL-hNy" id="UhD-wi-jtK"/>
+                                    <outlet property="delegate" destination="ixd-IL-hNy" id="Alk-Fw-YWo"/>
                                 </connections>
                             </webView>
                         </subviews>
@@ -294,7 +294,7 @@ wanted with as little input and thought as possible.</string>
         <scene sceneID="smW-Zh-WAh">
             <objects>
                 <tableViewController storyboardIdentifier="Posts View Controller" title="Posts" useStoryboardIdentifierAsRestorationIdentifier="YES" id="7bK-jq-Zjz" customClass="PostsViewController" sceneMemberID="viewController">
-                    <tableView key="view" clipsSubviews="YES" contentMode="scaleToFill" alwaysBounceVertical="YES" dataMode="prototypes" style="grouped" separatorStyle="singleLineEtched" rowHeight="44" sectionHeaderHeight="10" sectionFooterHeight="10" id="r7i-6Z-zg0">
+                    <tableView key="view" clipsSubviews="YES" contentMode="scaleToFill" restorationIdentifier="Posts Table View" alwaysBounceVertical="YES" dataMode="prototypes" style="grouped" separatorStyle="singleLineEtched" rowHeight="44" sectionHeaderHeight="10" sectionFooterHeight="10" id="r7i-6Z-zg0">
                         <rect key="frame" x="0.0" y="0.0" width="600" height="536"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <color key="backgroundColor" red="0.66666666669999997" green="0.0" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
diff --git a/Blog/EditorViewController.m b/Blog/EditorViewController.m
index 3d69062..1a0a944 100644
--- a/Blog/EditorViewController.m
+++ b/Blog/EditorViewController.m
@@ -212,13 +212,11 @@
 
 static NSString *const StateRestorationPostKey = @"post";
 static NSString *const StateRestorationModifiedPostKey = @"modifiedPost";
-static NSString *const StateRestorationTextViewContentOffsetKey = @"textView.contentOffset";
 
 - (void)encodeRestorableStateWithCoder:(NSCoder *)coder {
     NSLog(@"%@ encode restorable state with coder %@", self, coder);
     [coder encodeObject:self.post forKey:StateRestorationPostKey];
     [coder encodeObject:self.modifiedPost forKey:StateRestorationModifiedPostKey];
-    [coder encodeCGPoint:self.textView.contentOffset forKey:StateRestorationTextViewContentOffsetKey];
     [super encodeRestorableStateWithCoder:coder];
 }
 
@@ -226,7 +224,6 @@ static NSString *const StateRestorationTextViewContentOffsetKey = @"textView.con
     NSLog(@"%@ decode restorable state with coder %@", self, coder);
     self.post = [coder decodeObjectForKey:StateRestorationPostKey];
     self.modifiedPost = [coder decodeObjectForKey:StateRestorationModifiedPostKey];
-    self.textView.contentOffset = [coder decodeCGPointForKey:StateRestorationTextViewContentOffsetKey];
     [super decodeRestorableStateWithCoder:coder];
 }
 
diff --git a/Blog/PostsViewController.m b/Blog/PostsViewController.m
index 4c08f87..70b08d4 100644
--- a/Blog/PostsViewController.m
+++ b/Blog/PostsViewController.m
@@ -249,14 +249,12 @@ static const NSUInteger SectionPublished = 1;
 static NSString *const StateRestorationPostCollectionsKey = @"postCollections";
 static NSString *const StateRestorationBlogStatusDateKey = @"blogStatusDate";
 static NSString *const StateRestorationBlogStatusTextKey = @"blogStatusText";
-static NSString *const StateRestorationTabelViewContentOffsetKey = @"tableView.contentOffset";
 
 - (void)encodeRestorableStateWithCoder:(NSCoder *)coder  {
     NSLog(@"%@ encode restorable state with coder %@", self, coder);
     [coder encodeObject:self.postCollections forKey:StateRestorationPostCollectionsKey];
     [coder encodeObject:self.blogStatusDate forKey:StateRestorationBlogStatusDateKey];
     [coder encodeObject:self.blogStatusText forKey:StateRestorationBlogStatusTextKey];
-    [coder encodeCGPoint:self.tableView.contentOffset forKey:StateRestorationTabelViewContentOffsetKey];
     [super encodeRestorableStateWithCoder:coder];
 }
 
@@ -265,7 +263,6 @@ static NSString *const StateRestorationTabelViewContentOffsetKey = @"tableView.c
     self.postCollections = [coder decodeObjectForKey:StateRestorationPostCollectionsKey];
     self.blogStatusDate = [coder decodeObjectForKey:StateRestorationBlogStatusDateKey];
     self.blogStatusText = [coder decodeObjectForKey:StateRestorationBlogStatusTextKey];
-    self.tableView.contentOffset = [coder decodeCGPointForKey:StateRestorationTabelViewContentOffsetKey];
     [super decodeRestorableStateWithCoder:coder];
 }
 
diff --git a/Blog/PreviewViewController.m b/Blog/PreviewViewController.m
index 3a9bc96..28b55e9 100644
--- a/Blog/PreviewViewController.m
+++ b/Blog/PreviewViewController.m
@@ -19,6 +19,12 @@
 - (void)viewWillAppear:(BOOL)animated {
     [super viewWillAppear:animated];
 
+    // UIWebView restores its request so we just have to reload it
+    if (!self.initialRequest && self.webView.request) {
+        [self.webView reload];
+        return;
+    }
+
     if (self.initialRequest) {
         if (self.promise) {
             __weak __typeof__(self) welf = self;
@@ -29,10 +35,10 @@
                 __typeof__(self) self = welf;
                 self.promise = nil;
             });
+            return;
         }
-        else {
-            [self.webView loadRequest:self.initialRequest];
-        }
+        [self.webView loadRequest:self.initialRequest];
+        return;
     }
 }
 
@@ -41,28 +47,6 @@
     [self.webView loadHTMLString:@"<!doctype html><html><head><title></title></head><body></body></html>" baseURL:nil];
 }
 
-#pragma mark - State restoration
-
-static NSString *const StateRestorationInitialRequestKey = @"initialRequest";
-static NSString *const StateRestorationWebViewRequestURLKey = @"webView.request.URL";
-
-- (void)encodeRestorableStateWithCoder:(NSCoder *)coder {
-    [coder encodeObject:self.initialRequest forKey:StateRestorationInitialRequestKey];
-    [coder encodeObject:self.webView.request.URL forKey:StateRestorationWebViewRequestURLKey];
-    [super encodeRestorableStateWithCoder:coder];
-}
-
-- (void)decodeRestorableStateWithCoder:(NSCoder *)coder {
-    NSURL *url = [coder decodeObjectForKey:StateRestorationWebViewRequestURLKey];
-    if (url) {
-        [self.webView loadRequest:[NSURLRequest requestWithURL:url]];
-    }
-    else {
-        self.initialRequest = [coder decodeObjectForKey:StateRestorationInitialRequestKey];
-    }
-    [super decodeRestorableStateWithCoder:coder];
-}
-
 #pragma mark - UIWebViewDelegate methods
 
 - (void)webViewDidFinishLoad:(UIWebView *)webView {