gtk3: implement NWF CTRL_MULTILINE_EDITBOX

Change-Id: I1f86e262f64951d646ce74e3ceb225774afd7d1d

vcl/inc/unx/gtk/gtkgdi.hxx

@@ -66,6 +66,7 @@ private:
     GtkWidget       *mpWindow;
     static GtkStyleContext *mpButtonStyle;
     static GtkStyleContext *mpEntryStyle;
+    static GtkStyleContext *mpTextViewStyle;
     static GtkStyleContext *mpVScrollbarStyle;
     static GtkStyleContext *mpHScrollbarStyle;
     static GtkStyleContext *mpToolbarStyle;

vcl/unx/gtk3/gdi/gtk3salnativewidgets-gtk.cxx

@@ -22,6 +22,7 @@
 
 GtkStyleContext* GtkSalGraphics::mpButtonStyle = NULL;
 GtkStyleContext* GtkSalGraphics::mpEntryStyle = NULL;
+GtkStyleContext* GtkSalGraphics::mpTextViewStyle = NULL;
 GtkStyleContext* GtkSalGraphics::mpVScrollbarStyle = NULL;
 GtkStyleContext* GtkSalGraphics::mpHScrollbarStyle = NULL;
 GtkStyleContext* GtkSalGraphics::mpToolbarStyle = NULL;
@@ -840,6 +841,9 @@ bool GtkSalGraphics::drawNativeControl( ControlType nType, ControlPart nPart, co
     case CTRL_EDITBOX:
         context = mpEntryStyle;
         break;
+    case CTRL_MULTILINE_EDITBOX:
+        context = mpTextViewStyle;
+        break;
     case CTRL_COMBOBOX:
         context = mpComboboxStyle;
         renderType = RENDER_COMBOBOX;
@@ -1709,9 +1713,13 @@ bool GtkSalGraphics::IsNativeControlSupported( ControlType nType, ControlPart nP
             break;
 
         case CTRL_EDITBOX:
-//        case CTRL_MULTILINE_EDITBOX:
+        case CTRL_MULTILINE_EDITBOX:
+            if (nPart==PART_ENTIRE_CONTROL || nPart==HAS_BACKGROUND_TEXTURE)
+                return true;
+            break;
+
         case CTRL_COMBOBOX:
-            if(nPart==PART_ENTIRE_CONTROL || nPart==HAS_BACKGROUND_TEXTURE || nPart == PART_ALL_BUTTONS)
+            if (nPart==PART_ENTIRE_CONTROL || nPart==HAS_BACKGROUND_TEXTURE || nPart == PART_ALL_BUTTONS)
                 return true;
             break;
 
@@ -1886,6 +1894,7 @@ GtkSalGraphics::GtkSalGraphics( GtkSalFrame *pFrame, GtkWidget *pWindow )
 
     gEntryBox = gtk_entry_new();
     getStyleContext(&mpEntryStyle, gEntryBox);
+    getStyleContext(&mpTextViewStyle, gtk_text_view_new());
     getStyleContext(&mpButtonStyle, gtk_button_new());
 
     getStyleContext(&mpToolbarStyle, gtk_toolbar_new());