[geary/mjog/558-webkit-shared-process-redux: 93/102] Components.WebView: Convert to using messages for JS → client comms

[Michael Gratton <mjog src gnome org>]

commit fb96676fbd4ab7f413071f18cbf444cd7a953b77
Author: Michael Gratton <mike vee net>
Date:   Fri Aug 28 11:25:28 2020 +1000

    Components.WebView: Convert to using messages for JS → client comms

 src/client/components/components-web-view.vala | 79 +++++++++++++-------------
 ui/components-web-view.js                      | 25 ++++----
 2 files changed, 53 insertions(+), 51 deletions(-)
---
diff --git a/src/client/components/components-web-view.vala b/src/client/components/components-web-view.vala
index c746c4410..a5cdfe332 100644
--- a/src/client/components/components-web-view.vala
+++ b/src/client/components/components-web-view.vala
@@ -1,6 +1,6 @@
 /*
- * Copyright 2016 Software Freedom Conservancy Inc.
- * Copyright 2016-2019 Michael Gratton <mike vee net>
+ * Copyright © 2016 Software Freedom Conservancy Inc.
+ * Copyright © 2016-2020 Michael Gratton <mike vee net>
  *
  * This software is licensed under the GNU Lesser General Public License
  * (version 2.1 or later). See the COPYING file in this distribution.
@@ -31,12 +31,12 @@ public abstract class Components.WebView : WebKit.WebView, Geary.BaseInterface {
     private const string MESSAGE_EXCEPTION_NAME = "__exception__";
 
     // WebKit message handler names
-    private const string COMMAND_STACK_CHANGED = "commandStackChanged";
-    private const string CONTENT_LOADED = "contentLoaded";
-    private const string DOCUMENT_MODIFIED = "documentModified";
-    private const string PREFERRED_HEIGHT_CHANGED = "preferredHeightChanged";
-    private const string REMOTE_IMAGE_LOAD_BLOCKED = "remoteImageLoadBlocked";
-    private const string SELECTION_CHANGED = "selectionChanged";
+    private const string COMMAND_STACK_CHANGED = "command_stack_changed";
+    private const string CONTENT_LOADED = "content_loaded";
+    private const string DOCUMENT_MODIFIED = "document_modified";
+    private const string PREFERRED_HEIGHT_CHANGED = "preferred_height_changed";
+    private const string REMOTE_IMAGE_LOAD_BLOCKED = "remote_image_load_blocked";
+    private const string SELECTION_CHANGED = "selection_changed";
 
     private const double ZOOM_DEFAULT = 1.0;
     private const double ZOOM_FACTOR = 0.1;
@@ -605,22 +605,22 @@ public abstract class Components.WebView : WebKit.WebView, Geary.BaseInterface {
                 warning("Web process crashed: %s", reason.to_string());
             });
 
-        register_message_handler(
+        register_message_callback(
             COMMAND_STACK_CHANGED, on_command_stack_changed
         );
-        register_message_handler(
+        register_message_callback(
             CONTENT_LOADED, on_content_loaded
         );
-        register_message_handler(
+        register_message_callback(
             DOCUMENT_MODIFIED, on_document_modified
         );
-        register_message_handler(
+        register_message_callback(
             PREFERRED_HEIGHT_CHANGED, on_preferred_height_changed
         );
-        register_message_handler(
+        register_message_callback(
             REMOTE_IMAGE_LOAD_BLOCKED, on_remote_image_load_blocked
         );
-        register_message_handler(
+        register_message_callback(
             SELECTION_CHANGED, on_selection_changed
         );
 
@@ -783,12 +783,12 @@ public abstract class Components.WebView : WebKit.WebView, Geary.BaseInterface {
         return false;
     }
 
-    private void on_preferred_height_changed(WebKit.JavascriptResult result) {
+    private void on_preferred_height_changed(GLib.Variant? parameters) {
         double height = this.webkit_reported_height;
-        try {
-            height = Util.JS.to_double(result.get_js_value());
-        } catch (Util.JS.Error err) {
-            debug("Could not get preferred height: %s", err.message);
+        if (parameters != null && parameters.classify() == DOUBLE) {
+            height = parameters.get_double();
+        } else {
+            warning("Could not get JS preferred height");
         }
 
         if (this.webkit_reported_height != height) {
@@ -797,40 +797,39 @@ public abstract class Components.WebView : WebKit.WebView, Geary.BaseInterface {
         }
     }
 
-    private void on_command_stack_changed(WebKit.JavascriptResult result) {
-        try {
-            string[] values =
-                Util.JS.to_string(result.get_js_value()).split(",");
-            command_stack_changed(values[0] == "true", values[1] == "true");
-        } catch (Util.JS.Error err) {
-            debug("Could not get command stack state: %s", err.message);
+    private void on_command_stack_changed(GLib.Variant? parameters) {
+        if (parameters != null &&
+            parameters.is_container() &&
+            parameters.n_children() == 2) {
+            GLib.Variant can_undo = parameters.get_child_value(0);
+            GLib.Variant can_redo = parameters.get_child_value(1);
+            command_stack_changed(
+                can_undo.classify() == BOOLEAN && can_undo.get_boolean(),
+                can_redo.classify() == BOOLEAN && can_redo.get_boolean()
+            );
+        } else {
+            warning("Could not get JS command stack state");
         }
     }
 
-    private void on_document_modified(WebKit.JavascriptResult result) {
+    private void on_document_modified(GLib.Variant? parameters) {
         document_modified();
     }
 
-    private void on_remote_image_load_blocked(WebKit.JavascriptResult result) {
+    private void on_remote_image_load_blocked(GLib.Variant? parameters) {
         remote_image_load_blocked();
     }
 
-    private void on_content_loaded(WebKit.JavascriptResult result) {
+    private void on_content_loaded(GLib.Variant? parameters) {
         this.is_content_loaded = true;
         content_loaded();
     }
 
-    private void on_selection_changed(WebKit.JavascriptResult result) {
-        try {
-            bool has_selection = Util.JS.to_bool(result.get_js_value());
-            // Avoid firing multiple notifies if the value hasn't
-            // changed
-            if (this.has_selection != has_selection) {
-                this.has_selection = has_selection;
-            }
-            selection_changed(has_selection);
-        } catch (Util.JS.Error err) {
-            debug("Could not get selection content: %s", err.message);
+    private void on_selection_changed(GLib.Variant? parameters) {
+        if (parameters != null && parameters.classify() == BOOLEAN) {
+            selection_changed(parameters.get_boolean());
+        } else {
+            warning("Could not get JS selection value");
         }
     }
 
diff --git a/ui/components-web-view.js b/ui/components-web-view.js
index 35e82dfcb..29b6acd57 100644
--- a/ui/components-web-view.js
+++ b/ui/components-web-view.js
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Michael Gratton <mike vee net>
+ * Copyright © 2016-2020 Michael Gratton <mike vee net>
  *
  * This software is licensed under the GNU Lesser General Public License
  * (version 2.1 or later). See the COPYING file in this distribution.
@@ -20,6 +20,13 @@ PageState.prototype = {
         this.hasSelection = false;
         this.lastPreferredHeight = 0;
 
+        this._selectionChanged = MessageSender("selection_changed");
+        this._contentLoaded = MessageSender("content_loaded");
+        this._remoteImageLoadBlocked = MessageSender("remote_image_load_blocked");
+        this._preferredHeightChanged = MessageSender("preferred_height_changed");
+        this._commandStackChanged = MessageSender("command_stack_changed");
+        this._documentModified = MessageSender("document_modified");
+
         let state = this;
 
         // Set up an observer to keep track of modifications made to
@@ -106,7 +113,7 @@ PageState.prototype = {
         // be vaguegly correct when notifying of the HTML load
         // completing.
         this.updatePreferredHeight();
-        window.webkit.messageHandlers.contentLoaded.postMessage(null);
+        this._contentLoaded();
     },
     loadRemoteImages: function() {
         window._gearyAllowRemoteResourceLoads = true;
@@ -142,7 +149,7 @@ PageState.prototype = {
         this.bodyObserver.disconnect();
     },
     remoteImageLoadBlocked: function() {
-        window.webkit.messageHandlers.remoteImageLoadBlocked.postMessage(null);
+        this._remoteImageLoadBlocked();
     },
     /**
      * Sends "preferredHeightChanged" message if it has changed.
@@ -160,9 +167,7 @@ PageState.prototype = {
         // shrink again, leading to visual flicker.
         if (this.isLoaded && height > 0 && height != this.lastPreferredHeight) {
             this.lastPreferredHeight = height;
-            window.webkit.messageHandlers.preferredHeightChanged.postMessage(
-                height
-            );
+            this._preferredHeightChanged(height);
         }
     },
     checkCommandStack: function() {
@@ -172,19 +177,17 @@ PageState.prototype = {
         if (canUndo != this.undoEnabled || canRedo != this.redoEnabled) {
             this.undoEnabled = canUndo;
             this.redoEnabled = canRedo;
-            window.webkit.messageHandlers.commandStackChanged.postMessage(
-                this.undoEnabled + "," + this.redoEnabled
-            );
+            this._commandStackChanged(this.undoEnabled, this.redoEnabled);
         }
     },
     documentModified: function(element) {
-        window.webkit.messageHandlers.documentModified.postMessage(null);
+        this._documentModified();
     },
     selectionChanged: function() {
         let hasSelection = !window.getSelection().isCollapsed;
         if (this.hasSelection != hasSelection) {
             this.hasSelection = hasSelection;
-            window.webkit.messageHandlers.selectionChanged.postMessage(hasSelection);
+            this._selectionChanged(hasSelection);
         }
     },
     // Methods below are for unit tests.