LV2EffectMeter.cpp

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  @file LV2EffectMeter.cpp
 
  Paul Licameli split from LV2Effect.cpp
 
  Audacity(R) is copyright (c) 1999-2008 Audacity Team.
  License: GPL v2 or later.  See License.txt.
 
**********************************************************************/
 
#if defined(USE_LV2)
 
#if defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wparentheses"
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#elif defined(__clang__)
#pragma clang diagnostic ignored "-Wparentheses"
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
#endif
 
#include "LV2EffectMeter.h"
#include <wx/dcbuffer.h>
 
BEGIN_EVENT_TABLE(LV2EffectMeter, wxWindow)
   EVT_IDLE(LV2EffectMeter::OnIdle)
   EVT_ERASE_BACKGROUND(LV2EffectMeter::OnErase)
   EVT_PAINT(LV2EffectMeter::OnPaint)
   EVT_SIZE(LV2EffectMeter::OnSize)
END_EVENT_TABLE()
 
LV2EffectMeter::LV2EffectMeter(
   wxWindow *parent, const LV2ControlPortPtr port, const float &value
)  : wxWindow{ parent, wxID_ANY, wxDefaultPosition, wxDefaultSize,
      wxSIMPLE_BORDER }
   , mControlPort(port)
   , mValue{ value }
{
   mLastValue = -value;
   SetBackgroundColour(*wxWHITE);
   SetMinSize({ 20, 20 });
}
 
LV2EffectMeter::~LV2EffectMeter()
{
}
 
void LV2EffectMeter::OnIdle(wxIdleEvent &evt)
{
   evt.Skip();
   if (!mConnected)
      return;
   if (mLastValue != mValue)
      Refresh(false);
}
 
void LV2EffectMeter::OnErase(wxEraseEvent &WXUNUSED(evt))
{
   // Just ignore it to prevent flashing
}
 
void LV2EffectMeter::OnPaint(wxPaintEvent &WXUNUSED(evt))
{
   if (!mConnected)
      return;
 
   std::unique_ptr<wxDC> dc {wxAutoBufferedPaintDCFactory(this)};
 
   // Cache some metrics
   wxRect r = GetClientRect();
   wxCoord x = r.GetLeft();
   wxCoord y = r.GetTop();
   wxCoord w = r.GetWidth();
   wxCoord h = r.GetHeight();
 
   // These use unscaled value, min, and max
   float val = std::clamp(mValue, mControlPort->mMin, mControlPort->mMax)
      - mControlPort->mMin;
 
   // Setup for erasing the background
   dc->SetPen(*wxTRANSPARENT_PEN);
   dc->SetBrush(wxColour(100, 100, 220));
 
   dc->Clear();
   dc->DrawRectangle(x, y, (w * (val / fabs(mControlPort->mMax - mControlPort->mMin))), h);
 
   mLastValue = mValue;
}
 
void LV2EffectMeter::OnSize(wxSizeEvent &WXUNUSED(evt))
{
   Refresh(false);
}
 
#endif