new class for widgets adjustable by rotation-like gestures

diff --git a/src/ui/widget/Makefile_insert b/src/ui/widget/Makefile_insert
index 11a5ef920d4b31702c3156f1a2433bbdfba547fc..c5bde795a02d1dfa44bc5f39b64ac8192e4a33dc 100644 (file)
--- a/src/ui/widget/Makefile_insert
+++ b/src/ui/widget/Makefile_insert
@@ -52,6 +52,8 @@ ui_widget_libuiwidget_a_SOURCES =     \
        ui/widget/registered-enums.h   \
        ui/widget/registry.cpp          \
        ui/widget/registry.h            \
+       ui/widget/rotateable.h            \
+       ui/widget/rotateable.cpp            \
        ui/widget/ruler.cpp             \
        ui/widget/ruler.h               \
        ui/widget/scalar-unit.cpp       \

diff --git a/src/ui/widget/rotateable.cpp b/src/ui/widget/rotateable.cpp
new file mode 100644 (file)
index 0000000..e434c10
--- /dev/null
+++ b/src/ui/widget/rotateable.cpp
@@ -0,0 +1,137 @@
+/**
+ * \brief widget adjustable by dragging it to rotate away from a zero-change axis
+ *
+ * Authors:
+ *   buliabyak@gmail.com
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL.  Read the file 'COPYING' for more information.
+ */
+
+#include "event-context.h"
+#include "rotateable.h"
+#include "libnr/nr-point.h"
+#include "libnr/nr-point-fns.h"
+#include <gtkmm/box.h>
+#include <gtkmm/eventbox.h>
+#include <glibmm/i18n.h>
+
+namespace Inkscape {
+namespace UI {
+namespace Widget {
+
+       Rotateable::Rotateable():
+    axis(-M_PI/4),
+    maxdecl(M_PI/4)
+  {
+               dragging = false;
+               working = false;
+               modifier = 0;
+               current_axis = axis;
+
+    signal_button_press_event().connect(sigc::mem_fun(*this, &Rotateable::on_click));
+    signal_motion_notify_event().connect(sigc::mem_fun(*this, &Rotateable::on_motion));
+    signal_button_release_event().connect(sigc::mem_fun(*this, &Rotateable::on_release));
+       }
+
+  bool Rotateable::on_click(GdkEventButton *event) {
+               if (event->button == 1) {
+                       drag_started_x = event->x;
+                       drag_started_y = event->y;
+                       modifier = get_single_modifier(modifier, event->state); 
+               dragging = true;
+               working = false;
+                       current_axis = axis;
+         return true;
+               } 
+               return false; 
+       }
+
+  guint Rotateable::get_single_modifier(guint old, guint state) {
+
+               if (old == 0) {
+                       if (state & GDK_CONTROL_MASK)
+                               return 1; // ctrl
+                       if (state & GDK_SHIFT_MASK)
+                               return 2; // shift
+                       return 0;
+               } else {
+                       if (!(state & GDK_CONTROL_MASK) && !(state & GDK_SHIFT_MASK))
+                               return 0; // none
+                       if (old == 1) 
+                       if (state & GDK_SHIFT_MASK && !(state & GDK_CONTROL_MASK))
+                               return 2; // shift
+        else 
+          return 1;
+                       if (old == 2) 
+                       if (state & GDK_CONTROL_MASK && !(state & GDK_SHIFT_MASK))
+                               return 1; // ctrl
+        else 
+          return 2;
+               return old;
+               }
+       }
+
+
+  bool Rotateable::on_motion(GdkEventMotion *event) {
+               if (dragging) {
+                       double dist = NR::L2(NR::Point(event->x, event->y) - NR::Point(drag_started_x, drag_started_y));
+                       double angle = atan2(event->y - drag_started_y, event->x - drag_started_x);
+                       if (dist > 20) {
+                               working = true;
+                       double force = CLAMP (-(angle - current_axis)/maxdecl, -1, 1);
+                       if (fabs(force) < 0.002)
+                               force = 0; // snap to zero
+                               if (modifier != get_single_modifier(modifier, event->state)) { 
+          // user has switched modifiers in mid drag, close past drag and start a new
+          // one, redefining axis temporarily
+                               do_release(force, modifier);
+                                       current_axis = angle;
+                       modifier = get_single_modifier(modifier, event->state); 
+                               } else {
+                               do_motion(force, modifier);
+                               }
+                       }
+      gobble_motion_events(GDK_BUTTON1_MASK);
+               return true;
+               } 
+               return false; 
+       }
+
+
+  bool Rotateable::on_release(GdkEventButton *event) {
+               if (dragging && working) {
+                       double angle = atan2(event->y - drag_started_y, event->x - drag_started_x);
+                       double force = CLAMP (-(angle - current_axis)/maxdecl, -1, 1);
+                       if (fabs(force) < 0.002)
+                               force = 0; // snap to zero
+                       do_release(force, modifier);
+                       dragging = false;
+                       working = false;
+                       current_axis = axis;
+                       return true;
+               }
+               return false;
+       }
+
+
+       Rotateable::~Rotateable() {
+       }
+
+
+
+} // namespace Widget
+} // namespace UI
+} // namespace Inkscape
+
+/* 
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=c++:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :

diff --git a/src/ui/widget/rotateable.h b/src/ui/widget/rotateable.h
new file mode 100644 (file)
index 0000000..65f3c59
--- /dev/null
+++ b/src/ui/widget/rotateable.h
@@ -0,0 +1,66 @@
+/**
+ * \brief widget adjustable by dragging it to rotate away from a zero-change axis
+ *
+ * Authors:
+ *   buliabyak@gmail.com
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL.  Read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_UI_ROTATEABLE_H
+#define INKSCAPE_UI_ROTATEABLE_H
+
+#include <gtkmm/box.h>
+#include <gtkmm/eventbox.h>
+#include <glibmm/i18n.h>
+
+namespace Inkscape {
+namespace UI {
+namespace Widget {
+
+class Rotateable: public Gtk::EventBox
+{
+public:
+       Rotateable();
+
+       ~Rotateable();
+
+  bool on_click(GdkEventButton *event);
+  bool on_motion(GdkEventMotion *event);
+  bool on_release(GdkEventButton *event);
+
+       double axis; 
+       double current_axis; 
+  double maxdecl; 
+
+private:
+  double drag_started_x;
+  double drag_started_y;
+       guint modifier;
+       bool dragging;
+       bool working;
+
+  guint get_single_modifier(guint old, guint state);
+
+       virtual void do_motion (double by, guint state) {}
+       virtual void do_release (double by, guint state) {}
+};
+
+} // namespace Widget
+} // namespace UI
+} // namespace Inkscape
+
+#endif // INKSCAPE_UI_ROTATEABLE_H
+
+/* 
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=c++:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :