From f5b4fc9a0b2c9518c73ddbc3b87a59ce5c4dbece Mon Sep 17 00:00:00 2001
From: Paddle <PaddleStroke@users.noreply.github.com>
Date: Mon, 8 Jan 2024 10:33:17 +0100
Subject: [PATCH] Property editor: Hide headers and enable resizing on all
 cells.

---
 src/Gui/propertyeditor/PropertyEditor.cpp | 59 +++++++++++++++++++++++
 src/Gui/propertyeditor/PropertyEditor.h   | 11 +++++
 2 files changed, 70 insertions(+)

diff --git a/src/Gui/propertyeditor/PropertyEditor.cpp b/src/Gui/propertyeditor/PropertyEditor.cpp
index d86e2629d9..b0b0e3489b 100644
--- a/src/Gui/propertyeditor/PropertyEditor.cpp
+++ b/src/Gui/propertyeditor/PropertyEditor.cpp
@@ -27,6 +27,7 @@
 # include <boost/algorithm/string/predicate.hpp>
 # include <QApplication>
 # include <QInputDialog>
+# include <QHeaderView>
 # include <QMenu>
 # include <QPainter>
 #endif
@@ -59,6 +60,7 @@ PropertyEditor::PropertyEditor(QWidget *parent)
     , binding(false)
     , checkDocument(false)
     , closingEditor(false)
+    , dragInProgress(false)
 {
     propertyModel = new PropertyModel(this);
     setModel(propertyModel);
@@ -93,6 +95,10 @@ PropertyEditor::PropertyEditor(QWidget *parent)
     connect(this, &QTreeView::collapsed, this, &PropertyEditor::onItemCollapsed);
     connect(propertyModel, &QAbstractItemModel::rowsMoved, this, &PropertyEditor::onRowsMoved);
     connect(propertyModel, &QAbstractItemModel::rowsRemoved, this, &PropertyEditor::onRowsRemoved);
+
+    setHeaderHidden(true);
+    viewport()->installEventFilter(this);
+    viewport()->setMouseTracking(true);
 }
 
 PropertyEditor::~PropertyEditor()
@@ -827,4 +833,57 @@ void PropertyEditor::contextMenuEvent(QContextMenuEvent *) {
     }
 }
 
+
+bool PropertyEditor::eventFilter(QObject* object, QEvent* event) {
+    if (object == viewport()) {
+        QMouseEvent* mouse_event = dynamic_cast<QMouseEvent*>(event);
+        if (mouse_event) {
+            if (mouse_event->type() == QEvent::MouseMove) {
+                if (dragInProgress) { // apply dragging
+                    QHeaderView* header_view = header();
+                    int delta = mouse_event->pos().x() - dragPreviousPos;
+                    dragPreviousPos = mouse_event->pos().x();
+                    //using minimal size = dragSensibility * 2 to prevent collapsing
+                    header_view->resizeSection(dragSection,
+                        qMax(dragSensibility * 2, header_view->sectionSize(dragSection) + delta));
+                    return true;
+                }
+                else { // set mouse cursor shape
+                    if (indexResizable(mouse_event->pos()).isValid()) {
+                        viewport()->setCursor(Qt::SplitHCursor);
+                    }
+                    else {
+                        viewport()->setCursor(QCursor());
+                    }
+                }
+            }
+            else if (mouse_event->type() == QEvent::MouseButtonPress && mouse_event->button() == Qt::LeftButton && !dragInProgress) {
+                if (indexResizable(mouse_event->pos()).isValid()) {
+                    dragInProgress = true;
+                    dragPreviousPos = mouse_event->x();
+                    dragSection = indexResizable(mouse_event->pos()).column();
+                    return true;
+                }
+            }
+            else if (mouse_event->type() == QEvent::MouseButtonRelease &&
+                mouse_event->button() == Qt::LeftButton && dragInProgress) { 
+                dragInProgress = false;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+QModelIndex PropertyEditor::indexResizable(QPoint mouse_pos) {
+    QModelIndex index = indexAt(mouse_pos - QPoint(dragSensibility + 1, 0));
+    if (index.isValid()) {
+        if (qAbs(visualRect(index).right() - mouse_pos.x()) < dragSensibility &&
+            header()->sectionResizeMode(index.column()) == QHeaderView::Interactive) {
+            return index;
+        }
+    }
+    return QModelIndex();
+}
+
 #include "moc_PropertyEditor.cpp"
diff --git a/src/Gui/propertyeditor/PropertyEditor.h b/src/Gui/propertyeditor/PropertyEditor.h
index 6f67e71766..bd01c2f99e 100644
--- a/src/Gui/propertyeditor/PropertyEditor.h
+++ b/src/Gui/propertyeditor/PropertyEditor.h
@@ -100,6 +100,7 @@ protected Q_SLOTS:
     void onRowsRemoved(const QModelIndex &parent, int start, int end);
 
 protected:
+    bool eventFilter(QObject* object, QEvent* event);
     void closeEditor (QWidget * editor, QAbstractItemDelegate::EndEditHint hint) override;
     void commitData (QWidget * editor) override;
     void editorDestroyed (QObject * editor) override;
@@ -120,6 +121,10 @@ private:
     void closeTransaction();
     void recomputeDocument(App::Document*);
 
+    // check if mouse_pos is around right or bottom side of a cell 
+    // and return the index of that cell if found
+    QModelIndex indexResizable(QPoint mouse_pos);
+
 private:
     PropertyItemDelegate *delegate;
     PropertyModel* propertyModel;
@@ -133,6 +138,12 @@ private:
     bool binding;
     bool checkDocument;
     bool closingEditor;
+    bool dragInProgress;
+
+    //max distance between mouse and a cell, small enough to trigger resize
+    int dragSensibility = 5; // NOLINT
+    int dragSection = 0;
+    int dragPreviousPos = 0;
 
     int transactionID = 0;