Partial fix to scroll overflow issues

[pulseview.git] / pv / view / view.cpp

diff --git a/pv/view/view.cpp b/pv/view/view.cpp
index 95b94cf1a0ab8d768fd966207dad1b92628aaf97..dcf60327680cae507f2fea2c08097cbfb98b62a5 100644 (file)
--- a/pv/view/view.cpp
+++ b/pv/view/view.cpp
@@ -19,6 +19,7 @@
  */
 
 #include <assert.h>
+#include <limits.h>
 #include <math.h>
 
 #include <boost/foreach.hpp>
@@ -47,6 +48,8 @@ const double View::MinScale = 1e-15;
 const int View::LabelMarginWidth = 70;
 const int View::RulerHeight = 30;
 
+const int View::MaxScrollValue = INT_MAX / 2;
+
 const int View::SignalHeight = 50;
 
 View::View(SigSession &session, QWidget *parent) :
@@ -119,6 +122,16 @@ void View::set_scale_offset(double scale, double offset)
        _viewport->update();
 }
 
+void View::get_scroll_layout(double &length, double &offset) const
+{
+       const shared_ptr<SignalData> sig_data = _session.get_data();
+       if(!sig_data)
+               return;
+
+       length = _data_length / (sig_data->get_samplerate() * _scale);
+       offset = _offset / _scale;
+}
+
 void View::update_scroll()
 {
        assert(_viewport);
@@ -127,17 +140,19 @@ void View::update_scroll()
 
        // Set the horizontal scroll bar
        double length = 0, offset = 0;
-       const shared_ptr<SignalData> sig_data = _session.get_data();
-       if(sig_data) {
-               length = _data_length /
-                       (sig_data->get_samplerate() * _scale);
-               offset = _offset / _scale;
-       }
+       get_scroll_layout(length, offset);
+       length = max(length - areaSize.width(), 0.0);
 
        horizontalScrollBar()->setPageStep(areaSize.width());
-       horizontalScrollBar()->setRange(0,
-               max((int)(length - areaSize.width()), 0));
-       horizontalScrollBar()->setSliderPosition(offset);
+
+       if(length < MaxScrollValue) {
+               horizontalScrollBar()->setRange(0, length);
+               horizontalScrollBar()->setSliderPosition(offset);
+       } else {
+               horizontalScrollBar()->setRange(0, MaxScrollValue);
+               horizontalScrollBar()->setSliderPosition(
+                       _offset * MaxScrollValue / (_scale * length));
+       }
 
        // Set the vertical scrollbar
        verticalScrollBar()->setPageStep(areaSize.height());
@@ -172,7 +187,15 @@ void View::resizeEvent(QResizeEvent *e)
 
 void View::h_scroll_value_changed(int value)
 {
-       _offset = _scale * value;
+       const int range = horizontalScrollBar()->maximum();
+       if(range < MaxScrollValue)
+               _offset = _scale * value;
+       else {
+               double length = 0, offset;
+               get_scroll_layout(length, offset);
+               _offset = _scale * length * value / MaxScrollValue;
+       }
+
        _ruler->update();
        _viewport->update();
 }