Replacing zoomIn and zoomOut buttons in the TimelinePanel with a new TimelineZoomScale widget

src/gui/widgets/timeline/timeline-zoom-scale.cpp

@@ -0,0 +1,115 @@
+/*
+  timeline-zoom-scale.cpp  -  Implementation of the zoom scale widget
+
+  Copyright (C)         Lumiera.org
+    2011,               Michael R. Fisher <mfisher31@gmail.com>
+
+  This program is free software; you can redistribute it and/or
+  modify it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 2 of
+  the License, or (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+* *****************************************************/
+
+#include "gui/widgets/timeline/timeline-zoom-scale.hpp"
+#include "gui/widgets/timeline-widget.hpp"
+
+using namespace Gtk;
+
+namespace gui {
+namespace widgets {
+
+class TimelineWidget;
+
+namespace timeline {
+
+TimelineZoomScale::TimelineZoomScale()
+  : HBox()
+  , adjustment(0.5, 0.0, 1.0, 0.000001)
+  , slider()
+  , zoomIn(Stock::ZOOM_IN)
+  , zoomOut(Stock::ZOOM_OUT)
+  , smoothing_factor(9.0)
+  , button_step_size(0.03)
+{
+  /* Setup the Slider Control */
+  slider.set_adjustment(adjustment);
+  slider.set_size_request(123,10);
+  slider.set_digits(6);
+  slider.set_inverted(true);
+  slider.set_draw_value(false);
+
+  /* Make our connections */
+  zoomIn.signal_clicked().
+      connect(sigc::mem_fun(this, &TimelineZoomScale::on_zoom_in_clicked));
+
+  zoomOut.signal_clicked().
+      connect(sigc::mem_fun(this, &TimelineZoomScale::on_zoom_out_clicked));
+
+  adjustment.signal_value_changed().
+      connect(sigc::mem_fun(this, &TimelineZoomScale::on_zoom));
+
+  /* Add Our Widgets and show them */
+  pack_start(zoomOut,PACK_SHRINK);
+  pack_start(slider,PACK_SHRINK);
+  pack_start(zoomIn,PACK_SHRINK);
+
+  show_all();
+}
+
+void
+TimelineZoomScale::on_zoom_in_clicked()
+{
+  double newValue = adjustment.get_value() - button_step_size;
+  adjustment.set_value(newValue);
+}
+
+void
+TimelineZoomScale::on_zoom_out_clicked()
+{
+  double newValue = adjustment.get_value() + button_step_size;
+  adjustment.set_value(newValue);
+}
+
+void
+TimelineZoomScale::on_zoom()
+{
+  zoomSignal.emit(calculate_zoom_scale()) ;
+}
+
+sigc::signal<void, int64_t>
+TimelineZoomScale::signal_zoom()
+{
+  return zoomSignal;
+}
+
+int64_t
+TimelineZoomScale::calculate_zoom_scale()
+{
+  int64_t zoom_scale = 0;
+
+  double smoothed = pow(adjustment.get_value(), smoothing_factor);
+  zoom_scale = (int64_t)( smoothed * (double)TimelineWidget::MaxScale);
+
+  /* Prevent Zooming in To Close and Far */
+  if(zoom_scale < 1)
+    zoom_scale = 1;
+
+  if(zoom_scale > TimelineWidget::MaxScale)
+    zoom_scale = TimelineWidget::MaxScale;
+
+  return zoom_scale;
+}
+
+} // namespace gui
+} // namespace widgets
+} // namespace timeline

src/gui/widgets/timeline/timeline-zoom-scale.hpp

@@ -0,0 +1,99 @@
+/*
+  timeline-zoom-scale.hpp  -  Declaration of the zoom scale widget
+
+  Copyright (C)         Lumiera.org
+    2011,               Michael R. Fisher <mfisher31@gmail.com>
+
+  This program is free software; you can redistribute it and/or
+  modify it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 2 of
+  the License, or (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+/** @file timeline-zoom-scale.hpp
+ ** This file contains the definition of the zoom scale widget
+ */
+
+#ifndef TIMELINE_ZOOM_SCALE_HPP
+#define TIMELINE_ZOOM_SCALE_HPP
+
+#include "gui/gtk-lumiera.hpp"
+#include "gui/widgets/mini-button.hpp"
+
+using namespace Gtk;
+using namespace gui::widgets;
+
+namespace gui {
+namespace widgets {
+namespace timeline {
+
+class TimelineZoomScale : public Gtk::HBox
+{
+public:
+  /**
+   * Constructor
+   */
+  TimelineZoomScale();
+
+  /**
+   * Accessor method to the zoomSignal
+   * @return the zoomSignal
+   */
+  sigc::signal<void, int64_t> signal_zoom();
+
+private:
+  /* Event Handlers */
+
+  /**
+   * Event handler for when the zoomIn Button
+   * is clicked
+   */
+  void on_zoom_in_clicked();
+
+  /**
+   * Event handler for when the zoomIn Button
+   * is clicked
+   */
+  void on_zoom_out_clicked();
+
+  /**
+   * Event handler for when the adjustment
+   * value is changed
+   */
+  void on_zoom();
+
+  /**
+   * Calculate a Zoom Scale value based on
+   * the adjustment's current value
+   * @return The Zoom Scale value
+   */
+  int64_t calculate_zoom_scale();
+
+  /* Widgets */
+  Gtk::Adjustment adjustment;
+  Gtk::HScale slider;
+  MiniButton zoomIn;
+  MiniButton zoomOut;
+
+protected:
+  /* Signals */
+  sigc::signal<void, int64_t> zoomSignal;
+
+  const double smoothing_factor;
+  const double button_step_size;
+};
+
+} // namespace gui
+} // namespace widgets
+} // namespace timeline
+
+#endif /* TIMELINE_ZOOM_SCALE_HPP */