I18n: Add translation contexts to node panels

Node UIs can now have panels. Some of those may need to have their
labels translated using translation contexts. PanelDeclarations
already had a translation_context member, this commit adds a way to
specify this context, and to use it for translation on drawing the
node.

Pull Request: https://projects.blender.org/blender/blender/pulls/139124

source/blender/editors/interface/templates/interface_template_node_inputs.cc

@@ -107,7 +107,11 @@ static void draw_node_inputs_recursive(bContext *C,
   PanelLayout panel = layout->panel(C, panel_idname, panel_decl.default_collapsed);
   const bool has_used_inputs = panel_has_input_affecting_node_output(node, panel_decl);
   uiLayoutSetActive(panel.header, has_used_inputs);
-  panel.header->label(IFACE_(panel_decl.name), ICON_NONE);
+
+  const char *panel_translation_context = (panel_decl.translation_context.has_value() ?
+                                               panel_decl.translation_context->c_str() :
+                                               nullptr);
+  panel.header->label(CTX_IFACE_(panel_translation_context, panel_decl.name), ICON_NONE);
   if (!panel.body) {
     return;
   }

source/blender/editors/space_node/node_draw.cc

@@ -2633,11 +2633,14 @@ static void node_draw_panels(bNodeTree &ntree, const bNode &node, uiBlock &block
     }
 
     /* Panel label. */
+    const char *panel_translation_context = (panel_decl.translation_context.has_value() ?
+                                                 panel_decl.translation_context->c_str() :
+                                                 nullptr);
     uiBut *label_but = uiDefBut(
         &block,
         UI_BTYPE_LABEL,
         0,
-        IFACE_(panel_decl.name),
+        CTX_IFACE_(panel_translation_context, panel_decl.name),
         offsetx,
         int(*panel_runtime.header_center_y - NODE_DYS),
         short(draw_bounds.xmax - draw_bounds.xmin - (30.0f * UI_SCALE_FAC)),

source/blender/nodes/NOD_node_declaration.hh

@@ -535,6 +535,7 @@ class PanelDeclarationBuilder : public DeclarationListBuilder {
   }
 
   Self &description(std::string value = "");
+  Self &translation_context(std::optional<std::string> value = std::nullopt);
   Self &default_closed(bool closed);
 };
 

source/blender/nodes/composite/nodes/node_composite_keying.cc

@@ -50,7 +50,8 @@ static void cmp_node_keying_declare(NodeDeclarationBuilder &b)
           "luminance intact using a Gaussian blur of the given size")
       .compositor_expects_single_value();
 
-  PanelDeclarationBuilder &key_panel = b.add_panel("Key").default_closed(true);
+  PanelDeclarationBuilder &key_panel = b.add_panel("Key").default_closed(true).translation_context(
+      BLT_I18NCONTEXT_ID_NODETREE);
   key_panel.add_input<decl::Float>("Balance", "Key Balance")
       .default_value(0.5f)
       .subtype(PROP_FACTOR)

source/blender/nodes/intern/node_declaration.cc

@@ -867,6 +867,13 @@ PanelDeclarationBuilder &PanelDeclarationBuilder::description(std::string value)
   return *this;
 }
 
+PanelDeclarationBuilder &PanelDeclarationBuilder::translation_context(
+    std::optional<std::string> value)
+{
+  decl_->translation_context = value;
+  return *this;
+}
+
 PanelDeclarationBuilder &PanelDeclarationBuilder::default_closed(bool closed)
 {
   decl_->default_collapsed = closed;