Refactor tweet screenshot code to a separate class and work around window disposal issues

Core/FormBrowser.cs

@@ -26,6 +26,12 @@ private static UserConfig Config{
 
         public string UpdateInstallerPath { get; private set; }
 
+        public FormNotification BrowserNotificationForm{
+            get{
+                return notification;
+            }
+        }
+
         private readonly ChromiumWebBrowser browser;
         private readonly PluginManager plugins;
         private readonly UpdateHandler updates;
@@ -38,6 +44,7 @@ private static UserConfig Config{
 
         private FormWindowState prevState;
 
+        private TweetScreenshotManager notificationScreenshotManager;
         private SoundPlayer notificationSound;
 
         public FormBrowser(PluginManager pluginManager, UpdaterSettings updaterSettings){
@@ -73,6 +80,10 @@ public FormBrowser(PluginManager pluginManager, UpdaterSettings updaterSettings)
             Disposed += (sender, args) => {
                 browser.Dispose();
 
+                if (notificationScreenshotManager != null){
+                    notificationScreenshotManager.Dispose();
+                }
+
                 if (notificationSound != null){
                     notificationSound.Dispose();
                 }
@@ -319,33 +330,11 @@ public void PlayNotificationSound(){
         }
 
         public void OnTweetScreenshotReady(string html, int width, int height){
-            FormNotification dummyWindow = CreateNotificationForm(NotificationFlags.DisableScripts | NotificationFlags.DisableContextMenu | NotificationFlags.TopMost);
+            if (notificationScreenshotManager == null){
+                notificationScreenshotManager = new TweetScreenshotManager(this);
+            }
 
-            dummyWindow.ShowNotificationForScreenshot(new TweetNotification(html, string.Empty, 0), width, height, () => {
-                Point? prevNotificationLocation = null;
-                bool prevFreezeTimer = false;
-
-                if (notification.IsNotificationVisible){
-                    prevNotificationLocation = notification.Location;
-                    prevFreezeTimer = notification.FreezeTimer;
-
-                    notification.Location = ControlExtensions.InvisibleLocation;
-                    notification.FreezeTimer = true;
-                }
-
-                dummyWindow.TakeScreenshot();
-                dummyWindow.Hide();
-                dummyWindow.Close();
-                // dummyWindow.Dispose(); // TODO something freezes the program sometimes
-
-                if (prevNotificationLocation.HasValue){
-                    notification.Location = prevNotificationLocation.Value;
-                    notification.FreezeTimer = prevFreezeTimer;
-                }
-            });
-            
-            dummyWindow.CanMoveWindow = () => false;
-            dummyWindow.Show();
+            notificationScreenshotManager.Trigger(html, width, height);
         }
 
         public void DisplayTooltip(string text){

Core/FormNotification.cs

@@ -28,7 +28,7 @@ public bool IsNotificationVisible{
             }
         }
 
-        private readonly Form owner;
+        private readonly Control owner;
         private readonly PluginManager plugins;
         private readonly ChromiumWebBrowser browser;
         private readonly NotificationFlags flags;
@@ -101,11 +101,6 @@ public FormNotification(FormBrowser owner, PluginManager pluginManager, Notifica
 
             owner.FormClosed += (sender, args) => Close();
 
-            if (!flags.HasFlag(NotificationFlags.DisableScripts)){
-                notificationJS = ScriptLoader.LoadResource(NotificationScriptFile);
-                pluginJS = ScriptLoader.LoadResource(PluginManager.PluginNotificationScriptFile);
-            }
-
             browser = new ChromiumWebBrowser("about:blank"){
                 MenuHandler = new ContextMenuNotification(this, !flags.HasFlag(NotificationFlags.DisableContextMenu)),
                 LifeSpanHandler = new LifeSpanHandler()
@@ -117,8 +112,16 @@ public FormNotification(FormBrowser owner, PluginManager pluginManager, Notifica
 
             browser.IsBrowserInitializedChanged += Browser_IsBrowserInitializedChanged;
             browser.FrameLoadEnd += Browser_FrameLoadEnd;
-            browser.RegisterJsObject("$TD", new TweetDeckBridge(owner, this));
-            browser.RegisterAsyncJsObject("$TDP", plugins.Bridge);
+
+            if (!flags.HasFlag(NotificationFlags.DisableScripts)){
+                notificationJS = ScriptLoader.LoadResource(NotificationScriptFile);
+                browser.RegisterJsObject("$TD", new TweetDeckBridge(owner, this));
+
+                if (plugins != null){
+                    pluginJS = ScriptLoader.LoadResource(PluginManager.PluginNotificationScriptFile);
+                    browser.RegisterAsyncJsObject("$TDP", plugins.Bridge);
+                }
+            }
 
             panelBrowser.Controls.Add(browser);
 
@@ -210,7 +213,7 @@ private void Browser_FrameLoadEnd(object sender, FrameLoadEndEventArgs e){
             else if (notificationJS != null && browser.Address != "about:blank" && !flags.HasFlag(NotificationFlags.DisableScripts)){
                 ScriptLoader.ExecuteScript(e.Frame, notificationJS, NotificationScriptIdentifier);
 
-                if (plugins.HasAnyPlugin(PluginEnvironment.Notification)){
+                if (plugins != null && plugins.HasAnyPlugin(PluginEnvironment.Notification)){
                     ScriptLoader.ExecuteScript(e.Frame, pluginJS, PluginScriptIdentifier);
                     ScriptLoader.ExecuteFile(e.Frame, PluginManager.PluginGlobalScriptFile);
                     plugins.ExecutePlugins(e.Frame, PluginEnvironment.Notification, false);
@@ -256,29 +259,32 @@ public void ShowNotificationForSettings(bool reset){
             }
         }
 
-        public void ShowNotificationForScreenshot(TweetNotification tweet, int width, int height, Action callback){
+        public void PrepareNotificationForScreenshot(Action callback){
             browser.RegisterAsyncJsObject("$TD_NotificationScreenshot", new CallbackBridge(this, callback));
 
             browser.FrameLoadEnd += (sender, args) => {
-                if (args.Frame.IsMain){
+                if (args.Frame.IsMain && browser.Address != "about:blank"){
                     ScriptLoader.ExecuteScript(args.Frame, "window.setTimeout(() => $TD_NotificationScreenshot.trigger(), 25)", "gen:screenshot");
                 }
             };
+        }
 
+        public void LoadNotificationForScreenshot(TweetNotification tweet, int width, int height){
             browser.LoadHtml(tweet.GenerateHtml(enableCustomCSS: false), "http://tweetdeck.twitter.com/?"+DateTime.Now.Ticks);
             
             Location = ControlExtensions.InvisibleLocation;
             ClientSize = new Size(width, height);
             progressBarTimer.Visible = false;
             panelBrowser.Height = height;
-
-            // TODO start a timer on 10 seconds to close the window if anything fails or takes too long
         }
 
-        public void TakeScreenshot(){
+        public void TakeScreenshotAndHide(){
             MoveToVisibleLocation();
             Activate();
             SendKeys.SendWait("%{PRTSC}");
+            
+            Location = ControlExtensions.InvisibleLocation;
+            browser.LoadHtml("", "about:blank");
         }
 
         public void HideNotification(bool loadBlank){

Core/Utils/Notification/TweetScreenshotManager.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Drawing;
+using TweetDck.Core.Controls;
+using TweetDck.Core.Handling;
+
+namespace TweetDck.Core.Utils.Notification{
+    class TweetScreenshotManager : IDisposable{
+        private readonly FormBrowser browser;
+        private readonly FormNotification screenshot;
+
+        public TweetScreenshotManager(FormBrowser browser){
+            this.browser = browser;
+
+            this.screenshot = new FormNotification(browser, null, NotificationFlags.DisableScripts | NotificationFlags.DisableContextMenu | NotificationFlags.TopMost){
+                CanMoveWindow = () => false
+            };
+
+            this.screenshot.PrepareNotificationForScreenshot(Callback);
+        }
+
+        public void Trigger(string html, int width, int height){
+            screenshot.LoadNotificationForScreenshot(new TweetNotification(html, string.Empty, 0), width, height);
+            screenshot.Show();
+
+            // TODO start a timer on 10 seconds to close the window if anything fails or takes too long
+        }
+
+        private void Callback(){
+            FormNotification notification = browser.BrowserNotificationForm;
+
+            Point? prevNotificationLocation = null;
+            bool prevFreezeTimer = false;
+
+            if (notification.IsNotificationVisible){
+                prevNotificationLocation = notification.Location;
+                prevFreezeTimer = notification.FreezeTimer;
+
+                notification.Location = ControlExtensions.InvisibleLocation;
+                notification.FreezeTimer = true;
+            }
+
+            screenshot.TakeScreenshotAndHide();
+
+            if (prevNotificationLocation.HasValue){
+                notification.Location = prevNotificationLocation.Value;
+                notification.FreezeTimer = prevFreezeTimer;
+            }
+        }
+
+        public void Dispose(){
+            screenshot.Dispose();
+        }
+    }
+}

TweetDck.csproj

@@ -178,6 +178,7 @@
     <Compile Include="Core\Utils\CommandLineArgs.cs" />
     <Compile Include="Core\Utils\CommandLineArgsParser.cs" />
     <Compile Include="Core\Utils\Notification\NotificationFlags.cs" />
+    <Compile Include="Core\Utils\Notification\TweetScreenshotManager.cs" />
     <Compile Include="Core\Utils\WindowState.cs" />
     <Compile Include="Core\Utils\WindowsUtils.cs" />
     <Compile Include="Core\Handling\TweetDeckBridge.cs" />