1 files changed, 117 insertions, 0 deletions
diff --git a/src/ui/widget/spinbutton.h b/src/ui/widget/spinbutton.h
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+++ b/src/ui/widget/spinbutton.h
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author:
+ *   Johan B. C. Engelen
+ *
+ * Copyright (C) 2011 Author
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_UI_WIDGET_SPINBUTTON_H
+#define INKSCAPE_UI_WIDGET_SPINBUTTON_H
+
+#include <gtkmm/spinbutton.h>
+
+namespace Inkscape {
+namespace UI {
+namespace Widget {
+
+class UnitMenu;
+class UnitTracker;
+
+/**
+ * SpinButton widget, that allows entry of simple math expressions (also units, when linked with UnitMenu),
+ * and allows entry of both '.' and ',' for the decimal, even when in numeric mode.
+ *
+ * Calling "set_numeric()" effectively disables the expression parsing. If no unit menu is linked, all unitlike characters are ignored.
+ */
+class SpinButton : public Gtk::SpinButton
+{
+public:
+  SpinButton(double climb_rate = 0.0, guint digits = 0)
+    : Gtk::SpinButton(climb_rate, digits),
+      _unit_menu(nullptr),
+      _unit_tracker(nullptr),
+      _on_focus_in_value(0.)
+  {
+      connect_signals();
+  };
+  explicit SpinButton(Glib::RefPtr<Gtk::Adjustment>& adjustment, double climb_rate = 0.0, guint digits = 0)
+    : Gtk::SpinButton(adjustment, climb_rate, digits),
+      _unit_menu(nullptr),
+      _unit_tracker(nullptr),
+      _on_focus_in_value(0.)
+  {
+      connect_signals();
+  };
+
+  ~SpinButton() override = default;
+
+  // noncopyable
+  SpinButton(const SpinButton&) = delete;
+  SpinButton& operator=(const SpinButton&) = delete;
+
+  void setUnitMenu(UnitMenu* unit_menu) { _unit_menu = unit_menu; };
+  
+  void addUnitTracker(UnitTracker* ut) { _unit_tracker = ut; };
+
+protected:
+  UnitMenu *_unit_menu; /// Linked unit menu for unit conversion in entered expressions.
+  UnitTracker *_unit_tracker; // Linked unit tracker for unit conversion in entered expressions.
+  double _on_focus_in_value;
+
+  void connect_signals();
+
+    /**
+     * This callback function should try to convert the entered text to a number and write it to newvalue.
+     * It calls a method to evaluate the (potential) mathematical expression.
+     *
+     * @retval false No conversion done, continue with default handler.
+     * @retval true  Conversion successful, don't call default handler. 
+     */
+    int on_input(double* newvalue) override;
+
+    /**
+     * When focus is obtained, save the value to enable undo later.
+     * @retval false continue with default handler.
+     * @retval true  don't call default handler. 
+     */
+    bool on_my_focus_in_event(GdkEventFocus* event);
+
+    /**
+     * When scroll is done.
+     * @retval false continue with default handler.
+     * @retval true  don't call default handler.
+     */
+    bool on_scroll_event(GdkEventScroll *event) override;
+    /**
+     * Handle specific keypress events, like Ctrl+Z.
+     *
+     * @retval false continue with default handler.
+     * @retval true  don't call default handler. 
+     */
+    bool on_my_key_press_event(GdkEventKey* event);
+
+    /**
+     * Undo the editing, by resetting the value upon when the spinbutton got focus.
+     */
+    void undo();
+};
+
+} // namespace Widget
+} // namespace UI
+} // namespace Inkscape
+
+#endif // INKSCAPE_UI_WIDGET_SPINBUTTON_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :