Bug 1531338 - [Linux/Gtk] Get and use Gtk theme text color for active/pressed button, r=dao,emilio

- Follow Gtk and get theme button text color directly from "button" CSS node instead of "button label"
- Provide new -moz-gtk-buttonactivetext color for active/pressed button text color
- Replace ButtonText color with -moz-gtk-buttonactivetext when it's appropriate

Differential Revision: https://phabricator.services.mozilla.com/D30566

--HG--
extra : moz-landing-system : lando

browser/themes/linux/places/organizer.css

@@ -64,12 +64,15 @@
   -moz-appearance: toolbarbutton;
 }
 
-#placesMenu > menu:active,
-#placesMenu > menu:hover,
-#placesMenu > menu[open] {
+#placesMenu > menu:hover {
   color: ButtonText;
 }
 
+#placesMenu > menu:active,
+#placesMenu > menu[open] {
+  color: -moz-gtk-buttonactivetext;
+}
+
 #placesMenu > menu::after {
   content: "";
   display: -moz-box;

layout/style/res/forms.css

@@ -244,6 +244,14 @@ select {
   overflow-clip-box: padding-box !important; /* bug 992447 */
 }
 
+%ifdef MOZ_WIDGET_GTK
+/* Comboboxes use button styles on Gtk so it's safe to
+ * use a button style here. */
+select:active:hover {
+  color: -moz-gtk-buttonactivetext;
+}
+%endif
+
 /* Need the "select[size][multiple]" selector to override the settings on
    'select[size="1"]', eg if one has <select size="1" multiple> */
 
@@ -696,9 +704,14 @@ button:active:hover,
 input[type="reset"]:active:hover,
 input[type="button"]:active:hover,
 input[type="submit"]:active:hover {
+%ifdef MOZ_WIDGET_GTK
+  color: -moz-gtk-buttonactivetext;
+%else
   color: ButtonText;
+%endif
 }
 
+
 button::-moz-focus-inner,
 input[type="color"]::-moz-focus-inner,
 input[type="reset"]::-moz-focus-inner,

servo/components/style/properties/longhands/color.mako.rs

@@ -35,6 +35,7 @@ pub mod system_colors {
                            -moz-eventreerow -moz-field -moz-fieldtext -moz-dialog -moz-dialogtext
                            -moz-dragtargetzone -moz-gtk-info-bar-text -moz-html-cellhighlight
                            -moz-html-cellhighlighttext -moz-mac-buttonactivetext
+                           -moz-gtk-buttonactivetext
                            -moz-mac-chrome-active -moz-mac-chrome-inactive
                            -moz-mac-defaultbuttontext -moz-mac-focusring -moz-mac-menuselect
                            -moz-mac-menushadow -moz-mac-menutextdisable -moz-mac-menutextselect

toolkit/themes/linux/global/button.css

@@ -37,6 +37,12 @@ button:hover:not(:-moz-any(:active,[disabled="true"],[open="true"],[checked="tru
   color: -moz-buttonhovertext;
 }
 
+/* .......... active state .......... */
+
+button:not([disabled="true"]):-moz-any(:hover:active,[open="true"]) {
+  color: -moz-gtk-buttonactivetext;
+}
+
 /* .......... disabled state .......... */
 
 button[disabled="true"] {

widget/LookAndFeel.h

@@ -134,6 +134,11 @@ class LookAndFeel {
     eColorID__moz_eventreerow,
     eColorID__moz_oddtreerow,
 
+    // colors needed by the Linux Gtk theme
+
+    // used to button text, when button is pressed
+    eColorID__moz_gtk_buttonactivetext,
+
     // colors needed by the Mac OS X theme
 
     // foreground color of :hover:active buttons

widget/gtk/nsLookAndFeel.cpp

@@ -429,6 +429,9 @@ nsresult nsLookAndFeel::NativeGetColor(ColorID aID, nscolor& aColor) {
     case eColorID__moz_buttonhovertext:
       aColor = mButtonHoverText;
       break;
+    case eColorID__moz_gtk_buttonactivetext:
+      aColor = mButtonActiveText;
+      break;
     case eColorID__moz_menuhover:
       aColor = mMenuHover;
       break;
@@ -1005,21 +1008,22 @@ void nsLookAndFeel::EnsureInit() {
   style = GetStyleContext(MOZ_GTK_BUTTON);
   {
     GtkStyleContext* labelStyle = CreateStyleForWidget(labelWidget, style);
-
     GetSystemFontInfo(labelStyle, &mButtonFontName, &mButtonFontStyle);
-
-    gtk_style_context_get_border_color(style, GTK_STATE_FLAG_NORMAL, &color);
-    mButtonDefault = GDK_RGBA_TO_NS_RGBA(color);
-    gtk_style_context_get_color(labelStyle, GTK_STATE_FLAG_NORMAL, &color);
-    mButtonText = GDK_RGBA_TO_NS_RGBA(color);
-    gtk_style_context_get_color(labelStyle, GTK_STATE_FLAG_PRELIGHT, &color);
-    mButtonHoverText = GDK_RGBA_TO_NS_RGBA(color);
-    gtk_style_context_get_background_color(style, GTK_STATE_FLAG_PRELIGHT,
-                                           &color);
-    mButtonHoverFace = GDK_RGBA_TO_NS_RGBA(color);
     g_object_unref(labelStyle);
   }
 
+  gtk_style_context_get_border_color(style, GTK_STATE_FLAG_NORMAL, &color);
+  mButtonDefault = GDK_RGBA_TO_NS_RGBA(color);
+  gtk_style_context_get_color(style, GTK_STATE_FLAG_NORMAL, &color);
+  mButtonText = GDK_RGBA_TO_NS_RGBA(color);
+  gtk_style_context_get_color(style, GTK_STATE_FLAG_PRELIGHT, &color);
+  mButtonHoverText = GDK_RGBA_TO_NS_RGBA(color);
+  gtk_style_context_get_color(style, GTK_STATE_FLAG_ACTIVE, &color);
+  mButtonActiveText = GDK_RGBA_TO_NS_RGBA(color);
+  gtk_style_context_get_background_color(style, GTK_STATE_FLAG_PRELIGHT,
+                                         &color);
+  mButtonHoverFace = GDK_RGBA_TO_NS_RGBA(color);
+
   // Combobox text color
   style = GetStyleContext(MOZ_GTK_COMBOBOX_ENTRY_TEXTAREA);
   gtk_style_context_get_color(style, GTK_STATE_FLAG_NORMAL, &color);

widget/gtk/nsLookAndFeel.h

@@ -65,6 +65,7 @@ class nsLookAndFeel final : public nsXPLookAndFeel {
   nscolor mButtonText = kBlack;
   nscolor mButtonHoverText = kBlack;
   nscolor mButtonHoverFace = kWhite;
+  nscolor mButtonActiveText = kBlack;
   nscolor mFrameOuterLightBorder = kBlack;
   nscolor mFrameInnerDarkBorder = kBlack;
   nscolor mOddCellBackground = kWhite;

widget/nsXPLookAndFeel.cpp

@@ -177,6 +177,7 @@ const char nsXPLookAndFeel::sColorPrefs[][41] = {
     "ui.-moz_menubarhovertext",
     "ui.-moz_eventreerow",
     "ui.-moz_oddtreerow",
+    "ui.-moz-gtk-buttonactivetext",
     "ui.-moz-mac-buttonactivetext",
     "ui.-moz_mac_chrome_active",
     "ui.-moz_mac_chrome_inactive",
@@ -646,6 +647,7 @@ nscolor nsXPLookAndFeel::GetStandinForNativeColor(ColorID aID) {
       result = NS_RGB(0x00, 0x00, 0x00);
       break;
     case eColorID__moz_oddtreerow:
+    case eColorID__moz_gtk_buttonactivetext:
       result = NS_RGB(0xFF, 0xFF, 0xFF);
       break;
     case eColorID__moz_mac_chrome_active: