Add GridModify tool, and visibility flag to grids

src/DrawingProgram/GridModifyTool.cpp

@@ -0,0 +1,38 @@
+#include "GridModifyTool.hpp"
+#include "DrawingProgram.hpp"
+#include "../MainProgram.hpp"
+#include "../DrawData.hpp"
+
+GridModifyTool::GridModifyTool(DrawingProgram& initDrawP):
+    DrawingProgramToolBase(initDrawP)
+{
+}
+
+void GridModifyTool::set_grid_name(const std::string& gridToModifyName) {
+    gridName = gridToModifyName;
+}
+
+DrawingProgramToolType GridModifyTool::get_type() {
+    return DrawingProgramToolType::GRIDMODIFY;
+}
+
+void GridModifyTool::gui_toolbox() {
+    Toolbar& t = drawP.world.main.toolbar;
+    t.gui.push_id("Grid modify tool");
+    t.gui.text_label_centered("Edit Grid");
+    t.gui.text_label_centered(gridName);
+    t.gui.pop_id();
+}
+
+void GridModifyTool::tool_update() {
+}
+
+bool GridModifyTool::prevent_undo_or_redo() {
+    return false;
+}
+
+void GridModifyTool::draw(SkCanvas* canvas, const DrawData& drawData) {
+}
+
+void GridModifyTool::switch_tool(DrawingProgramToolType newTool) {
+}