From e2c5c643d81da3f3a3b9238249da01a763a46dc1 Mon Sep 17 00:00:00 2001
From: wandererfan <wandererfan@gmail.com>
Date: Sun, 23 Nov 2025 18:04:39 -0500
Subject: [PATCH] [TD]convert transparency to alpha channel

---
 .../TechDraw/Gui/ViewProviderDrawingView.cpp  | 74 ++++++++++++++++---
 .../TechDraw/Gui/ViewProviderDrawingView.h    |  7 ++
 2 files changed, 70 insertions(+), 11 deletions(-)

diff --git a/src/Mod/TechDraw/Gui/ViewProviderDrawingView.cpp b/src/Mod/TechDraw/Gui/ViewProviderDrawingView.cpp
index 51906c2273..8cee4e87d2 100644
--- a/src/Mod/TechDraw/Gui/ViewProviderDrawingView.cpp
+++ b/src/Mod/TechDraw/Gui/ViewProviderDrawingView.cpp
@@ -25,7 +25,11 @@
 #include <boost/signals2.hpp>
 #include <boost/signals2/connection.hpp>
 
+#include <App/Application.h>
+#include <App/Document.h>
 #include <App/DocumentObject.h>
+#include <App/Metadata.h>
+#include <Base/Color.h>
 #include <Base/Console.h>
 #include <Gui/Application.h>
 #include <Gui/Control.h>
@@ -75,7 +79,6 @@ ViewProviderDrawingView::~ViewProviderDrawingView()
 
 void ViewProviderDrawingView::attach(App::DocumentObject *pcFeat)
 {
-//    Base::Console().message("VPDV::attach(%s)\n", pcFeat->getNameInDocument());
     ViewProviderDocumentObject::attach(pcFeat);
 
     //NOLINTBEGIN
@@ -209,11 +212,8 @@ void ViewProviderDrawingView::startRestoring()
 
 void ViewProviderDrawingView::finishRestoring()
 {
-    if (Visibility.getValue()) {
-        show();
-    } else {
-        hide();
-    }
+    fixColorAlphaValues();
+
     Gui::ViewProviderDocumentObject::finishRestoring();
 }
 
@@ -290,10 +290,10 @@ Gui::MDIView *ViewProviderDrawingView::getMDIView() const
 
 void ViewProviderDrawingView::onGuiRepaint(const TechDraw::DrawView* dv)
 {
-//    Base::Console().message("VPDV::onGuiRepaint(%s) - this: %x\n", dv->getNameInDocument(), this);
     Gui::Document* guiDoc = Gui::Application::Instance->getDocument(getViewObject()->getDocument());
-    if (!guiDoc)
+    if (!guiDoc) {
         return;
+    }
 
     std::vector<TechDraw::DrawPage*> pages = getViewObject()->findAllParentPages();
     if (pages.size() > 1) {
@@ -351,9 +351,7 @@ void ViewProviderDrawingView::onProgressMessage(const TechDraw::DrawView* dv,
                                               const std::string featureName,
                                               const std::string text)
 {
-//    Q_UNUSED(featureName)
     Q_UNUSED(dv)
-//    Q_UNUSED(text)
     showProgressMessage(featureName, text);
 }
 
@@ -481,7 +479,6 @@ TechDraw::DrawView* ViewProviderDrawingView::getViewObject() const
 //! handled by the undo mechanism, but the QGraphicsScene parentage is not reset.
 void ViewProviderDrawingView::fixSceneDependencies()
 {
-    Base::Console().message("VPDV::fixSceneDependencies()\n");
     auto page = getViewProviderPage();
     if (!page) {
         return;
@@ -526,3 +523,58 @@ std::vector<App::DocumentObject*> ViewProviderDrawingView::claimChildren() const
     return temp;
 }
 
+
+//! convert old style transparency values in PropertyColor to new style alpha channel values
+void ViewProviderDrawingView::fixColorAlphaValues()
+{
+    if (!Preferences::fixColorAlphaOnLoad() ||
+        checkMiniumumDocumentVersion(1, 1)) {
+        return;
+    }
+
+    // check every PropertyColor for transparency vs alpha
+    std::vector<App::Property*> allProperties;
+    getPropertyList(allProperties);
+
+    constexpr double alphaNone{0.0};
+    constexpr double alphaFull{1.0};
+
+    for (auto& prop : allProperties) {
+        auto* colorProp = freecad_cast<App::PropertyColor*>(prop);
+        if (colorProp) {
+            // Here we are assuming that transparent colors are not used/need not be converted.
+            // To invert more generally, colorOut.a = 1 - colorIn.a;, but we would need a different
+            // mechanism to determine when to do the conversion.
+            Base::Color colorTemp = colorProp->getValue();
+            if (colorTemp.a == alphaNone) {
+                colorTemp.a = alphaFull;
+                colorProp->setValue(colorTemp);
+            }
+        }
+    }
+}
+
+
+//! true if document toBeChecked was written by a program with version >= minMajor.minMinor.
+//! note that we can not check point releases as only the major and minor are recorded in the Document.xml
+//! file.
+//! (ex <Document SchemaVersion="4" ProgramVersion="1.2R44322 +1 (Git)" FileVersion="1" StringHasher="1">)
+bool ViewProviderDrawingView::checkMiniumumDocumentVersion(App::Document* toBeChecked,
+                                                           int minMajor,
+                                                           int minMinor)
+{
+    const char* docVersionText = toBeChecked->getProgramVersion();
+    int docMajor{0};
+    int docMinor{0};
+    // stole this bit from App::AttachExtension.
+    // NOLINTNEXTLINE
+    if (sscanf(docVersionText, "%d.%d", &docMajor, &docMinor) != 2) {
+        Base::Console().warning("Failed to retrieve document version number for %s\n",
+                    toBeChecked ? toBeChecked->getName() : "noname");
+        return false;   // ?? should we fail here? the file appears broken.
+    }
+
+    return std::tie(docMajor, docMinor) >= std::tie(minMajor, minMinor);
+}
+
+
diff --git a/src/Mod/TechDraw/Gui/ViewProviderDrawingView.h b/src/Mod/TechDraw/Gui/ViewProviderDrawingView.h
index 195026c57d..247fa61018 100644
--- a/src/Mod/TechDraw/Gui/ViewProviderDrawingView.h
+++ b/src/Mod/TechDraw/Gui/ViewProviderDrawingView.h
@@ -28,11 +28,13 @@
 
 #include <boost/signals2.hpp>
 
+#include <Gui/Document.h>
 #include <Gui/ViewProviderDocumentObject.h>
 #include <Mod/TechDraw/App/DrawView.h>
 
 #include "ViewProviderDrawingViewExtension.h"
 
+
 namespace TechDraw {
 class DrawView;
 }
@@ -102,6 +104,11 @@ public:
     virtual void fixSceneDependencies();
     std::vector<App::DocumentObject*> claimChildren() const override;
 
+    void fixColorAlphaValues();
+    bool checkMiniumumDocumentVersion(int minMajor, int minMinor) const
+        { return checkMiniumumDocumentVersion(this->getDocument()->getDocument(), minMajor, minMinor); }
+    static bool checkMiniumumDocumentVersion(App::Document* toBeChecked, int minMajor, int minMinor);
+
 
 private:
     void multiParentPaint(std::vector<TechDraw::DrawPage*>& pages);