From 1f3e35e95c52cf94dfde6a5aab7d6f2acc984e01 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Tue, 4 Apr 2023 18:02:16 +0200
Subject: [PATCH] Gui: allow to change background color and gradient from
 Python

---
 src/Gui/View3DViewerPy.cpp | 96 ++++++++++++++++++++++++++++++++++++--
 src/Gui/View3DViewerPy.h   |  2 +
 2 files changed, 94 insertions(+), 4 deletions(-)

diff --git a/src/Gui/View3DViewerPy.cpp b/src/Gui/View3DViewerPy.cpp
index d24a2ab063..2fa740d948 100644
--- a/src/Gui/View3DViewerPy.cpp
+++ b/src/Gui/View3DViewerPy.cpp
@@ -85,6 +85,10 @@ void View3DInventorViewerPy::init_type()
         "resetEditingRoot(updateLinks=True): restore the editing ViewProvider's root node");
     add_varargs_method("setBackgroundColor", &View3DInventorViewerPy::setBackgroundColor,
         "setBackgroundColor(r,g,b): sets the background color of the current viewer.");
+    add_varargs_method("setGradientBackground", &View3DInventorViewerPy::setGradientBackground,
+        "setGradientBackground(str): sets the background gradient of the current viewer.");
+    add_varargs_method("setGradientBackgroundColor", &View3DInventorViewerPy::setGradientBackgroundColor,
+        "setGradientBackgroundColor(tuple,tuple,[tuple]): sets the gradient colors of the current viewer.");
     add_varargs_method("setRedirectToSceneGraph", &View3DInventorViewerPy::setRedirectToSceneGraph,
         "setRedirectToSceneGraph(bool): enables or disables to redirect events directly to the scene graph.");
     add_varargs_method("isRedirectedToSceneGraph", &View3DInventorViewerPy::isRedirectedToSceneGraph,
@@ -429,15 +433,99 @@ Py::Object View3DInventorViewerPy::resetEditingRoot(const Py::Tuple& args)
     }
 }
 
-Py::Object View3DInventorViewerPy::setBackgroundColor(const Py::Tuple& args)
+Py::Object View3DInventorViewerPy::setGradientBackground(const Py::Tuple& args)
 {
-    float r,g,b = 0.0;
-    if (!PyArg_ParseTuple(args.ptr(), "fff", &r, &g, &b)) {
+    const char* background;
+    if (!PyArg_ParseTuple(args.ptr(), "s", &background)) {
         throw Py::Exception();
     }
     try {
-        SbColor col(r,g,b);
+        View3DInventorViewer::Background gradient = View3DInventorViewer::Background::NoGradient;
+        if (strcmp(background, "LINEAR") == 0) {
+            gradient = View3DInventorViewer::Background::LinearGradient;
+        }
+        else if (strcmp(background, "RADIAL") == 0) {
+            gradient = View3DInventorViewer::Background::RadialGradient;
+        }
+
+        _viewer->setGradientBackground(gradient);
+        _viewer->redraw();
+        return Py::None();
+    }
+    catch (const Base::Exception& e) {
+        throw Py::RuntimeError(e.what());
+    }
+    catch (const std::exception& e) {
+        throw Py::RuntimeError(e.what());
+    }
+    catch(...) {
+        throw Py::RuntimeError("Unknown C++ exception");
+    }
+}
+
+Py::Object View3DInventorViewerPy::setGradientBackgroundColor(const Py::Tuple& args)
+{
+    PyObject* col1;
+    PyObject* col2;
+    PyObject* col3 = nullptr;
+    if (!PyArg_ParseTuple(args.ptr(), "O!O!|O!",
+                          &PyTuple_Type, &col1,
+                          &PyTuple_Type, &col2,
+                          &PyTuple_Type, &col3)) {
+        throw Py::Exception();
+    }
+
+    auto tupleToColor = [](PyObject* col) {
+        SbColor color;
+        Py::Tuple tuple(col);
+        for (int i=0; i<3; i++) {
+            color[i] = static_cast<float>(Py::Float(tuple[i]));
+        }
+
+        return color;
+    };
+
+    try {
+        SbColor midColor(-1, -1, -1);
+        SbColor fromColor = tupleToColor(col1);
+        SbColor toColor = tupleToColor(col2);
+        if (col3) {
+            midColor = tupleToColor(col3);
+        }
+
+        _viewer->setGradientBackgroundColor(fromColor, toColor, midColor);
+        _viewer->redraw();
+        return Py::None();
+    }
+    catch (const Base::Exception& e) {
+        throw Py::RuntimeError(e.what());
+    }
+    catch (const std::exception& e) {
+        throw Py::RuntimeError(e.what());
+    }
+    catch(...) {
+        throw Py::RuntimeError("Unknown C++ exception");
+    }
+}
+
+Py::Object View3DInventorViewerPy::setBackgroundColor(const Py::Tuple& args)
+{
+    float red, green, blue = 0.0;
+    if (!PyArg_ParseTuple(args.ptr(), "fff", &red, &green, &blue)) {
+        throw Py::Exception();
+    }
+    try {
+        SbColor col(red, green, blue);
         _viewer->setGradientBackgroundColor(col, col);
+
+        QColor qtcolor;
+        qtcolor.setRedF(red);
+        qtcolor.setGreenF(green);
+        qtcolor.setBlueF(blue);
+        if (qtcolor.isValid()) {
+            _viewer->setBackgroundColor(qtcolor);
+        }
+        _viewer->redraw();
         return Py::None();
     }
     catch (const Base::Exception& e) {
diff --git a/src/Gui/View3DViewerPy.h b/src/Gui/View3DViewerPy.h
index b70d9243fd..e157c30be8 100644
--- a/src/Gui/View3DViewerPy.h
+++ b/src/Gui/View3DViewerPy.h
@@ -67,6 +67,8 @@ public:
     Py::Object setupEditingRoot(const Py::Tuple &args);
     Py::Object resetEditingRoot(const Py::Tuple &args);
 
+    Py::Object setGradientBackground(const Py::Tuple& args);
+    Py::Object setGradientBackgroundColor(const Py::Tuple& args);
     Py::Object setBackgroundColor(const Py::Tuple& args);
     Py::Object setRedirectToSceneGraph(const Py::Tuple& args);
     Py::Object isRedirectedToSceneGraph(const Py::Tuple& args);