[evolution] Add option to unset colors provided in HTML mails for preview into Preferences

[Milan Crha <mcrha src gnome org>]

commit ed36776c405565fb6909328d0578aa099e38d398
Author: Milan Crha <mcrha redhat com>
Date:   Tue Feb 1 11:23:40 2022 +0100

    Add option to unset colors provided in HTML mails for preview into Preferences
    
    It's located in Edit->Preferences->Mail Preferences->HTML Messages->Unset
    colors provided in HTML mails in message preview.
    
    Related to https://gitlab.gnome.org/GNOME/evolution/issues/695

 data/webkit/e-web-view.js          | 11 +++++++----
 src/mail/e-mail-display.c          | 34 +++++++++++++++++++++++++++++-----
 src/mail/mail-config.ui            | 18 +++++++++++++++++-
 src/modules/mail/em-mailer-prefs.c |  6 ++++++
 4 files changed, 59 insertions(+), 10 deletions(-)
---
diff --git a/data/webkit/e-web-view.js b/data/webkit/e-web-view.js
index c01707b070..7f47fe4b26 100644
--- a/data/webkit/e-web-view.js
+++ b/data/webkit/e-web-view.js
@@ -1069,10 +1069,10 @@ Evo.unsetHTMLColors = function(doc)
                                continue;
 
                        if (rule.style.color)
-                               rule.style.color = "inherit";
+                               rule.style.removeProperty("color");
 
                        if (rule.style.backgroundColor)
-                               rule.style.backgroundColor = "inherit";
+                               rule.style.removeProperty("background-color");
                }
        }
 
@@ -1086,10 +1086,13 @@ Evo.unsetHTMLColors = function(doc)
                if (elem.tagName != "HTML" && elem.tagName != "IFRAME" && elem.tagName != "INPUT" && 
elem.tagName != "BUTTON" && elem.tagName != "IMG") {
                        if (elem.style) {
                                if (elem.style.color)
-                                       elem.style.color = "inherit";
+                                       elem.style.removeProperty("color");
 
                                if (elem.style.backgroundColor)
-                                       elem.style.backgroundColor = "inherit";
+                                       elem.style.removeProperty("background-color");
+
+                               if (!elem.style.length)
+                                       elem.removeAttribute("style");
                        }
 
                        elem.removeAttribute("color");
diff --git a/src/mail/e-mail-display.c b/src/mail/e-mail-display.c
index ba0ec8892a..fabe6f9c94 100644
--- a/src/mail/e-mail-display.c
+++ b/src/mail/e-mail-display.c
@@ -2108,12 +2108,13 @@ mail_display_drag_data_get (GtkWidget *widget,
        g_free (uri);
 }
 
-static void
-e_mail_display_test_change_and_update_fonts_cb (EMailDisplay *mail_display,
-                                               const gchar *key,
-                                               GSettings *settings)
+static gboolean
+e_mail_display_test_key_changed (EMailDisplay *mail_display,
+                                const gchar *key,
+                                GSettings *settings)
 {
        GVariant *new_value, *old_value;
+       gboolean changed = FALSE;
 
        new_value = g_settings_get_value (settings, key);
        old_value = g_hash_table_lookup (mail_display->priv->old_settings, key);
@@ -2124,10 +2125,30 @@ e_mail_display_test_change_and_update_fonts_cb (EMailDisplay *mail_display,
                else
                        g_hash_table_remove (mail_display->priv->old_settings, key);
 
-               e_web_view_update_fonts (E_WEB_VIEW (mail_display));
+               changed = TRUE;
        } else if (new_value) {
                g_variant_unref (new_value);
        }
+
+       return changed;
+}
+
+static void
+e_mail_display_test_change_and_update_fonts_cb (EMailDisplay *mail_display,
+                                               const gchar *key,
+                                               GSettings *settings)
+{
+       if (e_mail_display_test_key_changed (mail_display, key, settings))
+               e_web_view_update_fonts (E_WEB_VIEW (mail_display));
+}
+
+static void
+e_mail_display_test_change_and_reload_cb (EMailDisplay *mail_display,
+                                         const gchar *key,
+                                         GSettings *settings)
+{
+       if (e_mail_display_test_key_changed (mail_display, key, settings))
+               e_mail_display_reload (mail_display);
 }
 
 static void
@@ -2408,6 +2429,9 @@ e_mail_display_init (EMailDisplay *display)
        g_signal_connect_swapped (
                display->priv->settings , "changed::use-custom-font",
                G_CALLBACK (e_mail_display_test_change_and_update_fonts_cb), display);
+       g_signal_connect_swapped (
+               display->priv->settings , "changed::preview-unset-html-colors",
+               G_CALLBACK (e_mail_display_test_change_and_reload_cb), display);
 
        g_signal_connect (
                display, "load-changed",
diff --git a/src/mail/mail-config.ui b/src/mail/mail-config.ui
index 7a92ef2d63..890837162a 100644
--- a/src/mail/mail-config.ui
+++ b/src/mail/mail-config.ui
@@ -2407,6 +2407,22 @@
                         <property name="position">0</property>
                       </packing>
                     </child>
+                    <child>
+                      <object class="GtkCheckButton" id="chkUnsetHTMLColors">
+                        <property name="label" translatable="yes">Unset colors provided in HTML mails in 
message previe_w</property>
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">False</property>
+                        <property name="use_underline">True</property>
+                        <property name="xalign">0.5</property>
+                        <property name="draw_indicator">True</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">False</property>
+                        <property name="position">1</property>
+                      </packing>
+                    </child>
                     <child>
                       <object class="GtkCheckButton" id="chkPromptWantHTML">
                         <property name="label" translatable="yes">_Prompt on sending HTML mail to contacts 
that do not want them</property>
@@ -2420,7 +2436,7 @@
                       <packing>
                         <property name="expand">False</property>
                         <property name="fill">False</property>
-                        <property name="position">1</property>
+                        <property name="position">2</property>
                       </packing>
                     </child>
                   </object>
diff --git a/src/modules/mail/em-mailer-prefs.c b/src/modules/mail/em-mailer-prefs.c
index e83fdf228c..fa5af4a2ea 100644
--- a/src/modules/mail/em-mailer-prefs.c
+++ b/src/modules/mail/em-mailer-prefs.c
@@ -1786,6 +1786,12 @@ em_mailer_prefs_construct (EMMailerPrefs *prefs,
                widget, "active",
                G_SETTINGS_BIND_DEFAULT);
 
+       widget = e_builder_get_widget (prefs->priv->builder, "chkUnsetHTMLColors");
+       g_settings_bind (
+               settings, "preview-unset-html-colors",
+               widget, "active",
+               G_SETTINGS_BIND_DEFAULT);
+
        widget = e_builder_get_widget (prefs->priv->builder, "chkPromptWantHTML");
        g_settings_bind (
                settings, "prompt-on-unwanted-html",