canvas.cpp

wxGTK 是 wxWidgets 的 linux GTK+ (>2.2.3)版本。wxWidgets 是一个跨平台的 GUI 框架

/////////////////////////////////////////////////////////////////////////////
// Name:        canvas.cpp
// Purpose:     Shape canvas class
// Author:      Julian Smart
// Modified by:
// Created:     12/07/98
// RCS-ID:      $Id: canvas.cpp,v 1.18 2005/10/06 18:17:21 ABX Exp $
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#ifndef WX_PRECOMP
#include "wx/wx.h"
#endif

#if wxUSE_PROLOGIO
#include "wx/deprecated/wxexpr.h"
#endif

#ifdef new
#undef new
#endif

#include <ctype.h>
#include <math.h>
#include <stdlib.h>

#include "wx/ogl/ogl.h"

#define CONTROL_POINT_SIZE       6

// Control point types
// Rectangle and most other shapes
#define CONTROL_POINT_VERTICAL   1
#define CONTROL_POINT_HORIZONTAL 2
#define CONTROL_POINT_DIAGONAL   3

// Line
#define CONTROL_POINT_ENDPOINT_TO 4
#define CONTROL_POINT_ENDPOINT_FROM 5
#define CONTROL_POINT_LINE       6

IMPLEMENT_DYNAMIC_CLASS(wxShapeCanvas, wxScrolledWindow)

BEGIN_EVENT_TABLE(wxShapeCanvas, wxScrolledWindow)
    EVT_PAINT(wxShapeCanvas::OnPaint)
    EVT_MOUSE_EVENTS(wxShapeCanvas::OnMouseEvent)
END_EVENT_TABLE()

const wxChar* wxShapeCanvasNameStr = wxT("shapeCanvas");

// Object canvas
wxShapeCanvas::wxShapeCanvas(wxWindow *parent, wxWindowID id,
                             const wxPoint& pos,
                             const wxSize& size,
                             long style,
                             const wxString& name):
  wxScrolledWindow(parent, id, pos, size, style, name)
{
  m_shapeDiagram = NULL;
  m_dragState = NoDragging;
  m_draggedShape = NULL;
  m_oldDragX = 0;
  m_oldDragY = 0;
  m_firstDragX = 0;
  m_firstDragY = 0;
  m_checkTolerance = true;
}

wxShapeCanvas::~wxShapeCanvas()
{
}

void wxShapeCanvas::OnPaint(wxPaintEvent& WXUNUSED(event))
{
    wxPaintDC dc(this);

    PrepareDC(dc);

    dc.SetBackground(wxBrush(GetBackgroundColour(), wxSOLID));
    dc.Clear();

    if (GetDiagram())
        GetDiagram()->Redraw(dc);
}

void wxShapeCanvas::OnMouseEvent(wxMouseEvent& event)
{
  wxClientDC dc(this);
  PrepareDC(dc);

  wxPoint logPos(event.GetLogicalPosition(dc));

  double x, y;
  x = (double) logPos.x;
  y = (double) logPos.y;

  int keys = 0;
  if (event.ShiftDown())
    keys = keys | KEY_SHIFT;
  if (event.ControlDown())
    keys = keys | KEY_CTRL;

  bool dragging = event.Dragging();

  // Check if we're within the tolerance for mouse movements.
  // If we're very close to the position we started dragging
  // from, this may not be an intentional drag at all.
  if (dragging)
  {
    int dx = abs(dc.LogicalToDeviceX((long) (x - m_firstDragX)));
    int dy = abs(dc.LogicalToDeviceY((long) (y - m_firstDragY)));
    if (m_checkTolerance && (dx <= GetDiagram()->GetMouseTolerance()) && (dy <= GetDiagram()->GetMouseTolerance()))
    {
      return;
    }
    else
      // If we've ignored the tolerance once, then ALWAYS ignore
      // tolerance in this drag, even if we come back within
      // the tolerance range.
      m_checkTolerance = false;
  }

  // Dragging - note that the effect of dragging is left entirely up
  // to the object, so no movement is done unless explicitly done by
  // object.
  if (dragging && m_draggedShape && m_dragState == StartDraggingLeft)
  {
    m_dragState = ContinueDraggingLeft;

    // If the object isn't m_draggable, transfer message to canvas
    if (m_draggedShape->Draggable())
      m_draggedShape->GetEventHandler()->OnBeginDragLeft((double)x, (double)y, keys, m_draggedAttachment);
    else
    {
      m_draggedShape = NULL;
      OnBeginDragLeft((double)x, (double)y, keys);
    }

    m_oldDragX = x; m_oldDragY = y;
  }
  else if (dragging && m_draggedShape && m_dragState == ContinueDraggingLeft)
  {
    // Continue dragging
    m_draggedShape->GetEventHandler()->OnDragLeft(false, m_oldDragX, m_oldDragY, keys, m_draggedAttachment);
    m_draggedShape->GetEventHandler()->OnDragLeft(true, (double)x, (double)y, keys, m_draggedAttachment);
    m_oldDragX = x; m_oldDragY = y;
  }
  else if (event.LeftUp() && m_draggedShape && m_dragState == ContinueDraggingLeft)
  {
    m_dragState = NoDragging;
    m_checkTolerance = true;

    m_draggedShape->GetEventHandler()->OnDragLeft(false, m_oldDragX, m_oldDragY, keys, m_draggedAttachment);

    m_draggedShape->GetEventHandler()->OnEndDragLeft((double)x, (double)y, keys, m_draggedAttachment);
    m_draggedShape = NULL;
  }
  else if (dragging && m_draggedShape && m_dragState == StartDraggingRight)
  {
    m_dragState = ContinueDraggingRight;

    if (m_draggedShape->Draggable())
      m_draggedShape->GetEventHandler()->OnBeginDragRight((double)x, (double)y, keys, m_draggedAttachment);
    else
    {
      m_draggedShape = NULL;
      OnBeginDragRight((double)x, (double)y, keys);
    }
    m_oldDragX = x; m_oldDragY = y;
  }
  else if (dragging && m_draggedShape && m_dragState == ContinueDraggingRight)
  {
    // Continue dragging
    m_draggedShape->GetEventHandler()->OnDragRight(false, m_oldDragX, m_oldDragY, keys, m_draggedAttachment);
    m_draggedShape->GetEventHandler()->OnDragRight(true, (double)x, (double)y, keys, m_draggedAttachment);
    m_oldDragX = x; m_oldDragY = y;
  }
  else if (event.RightUp() && m_draggedShape && m_dragState == ContinueDraggingRight)
  {
    m_dragState = NoDragging;
    m_checkTolerance = true;

    m_draggedShape->GetEventHandler()->OnDragRight(false, m_oldDragX, m_oldDragY, keys, m_draggedAttachment);

    m_draggedShape->GetEventHandler()->OnEndDragRight((double)x, (double)y, keys, m_draggedAttachment);
    m_draggedShape = NULL;
  }

  // All following events sent to canvas, not object
  else if (dragging && !m_draggedShape && m_dragState == StartDraggingLeft)
  {
    m_dragState = ContinueDraggingLeft;
    OnBeginDragLeft((double)x, (double)y, keys);
    m_oldDragX = x; m_oldDragY = y;
  }
  else if (dragging && !m_draggedShape && m_dragState == ContinueDraggingLeft)
  {
    // Continue dragging
    OnDragLeft(false, m_oldDragX, m_oldDragY, keys);
    OnDragLeft(true, (double)x, (double)y, keys);
    m_oldDragX = x; m_oldDragY = y;
  }
  else if (event.LeftUp() && !m_draggedShape && m_dragState == ContinueDraggingLeft)
  {
    m_dragState = NoDragging;
    m_checkTolerance = true;

    OnDragLeft(false, m_oldDragX, m_oldDragY, keys);
    OnEndDragLeft((double)x, (double)y, keys);
    m_draggedShape = NULL;
  }
  else if (dragging && !m_draggedShape && m_dragState == StartDraggingRight)
  {
    m_dragState = ContinueDraggingRight;
    OnBeginDragRight((double)x, (double)y, keys);
    m_oldDragX = x; m_oldDragY = y;
  }
  else if (dragging && !m_draggedShape && m_dragState == ContinueDraggingRight)
  {
    // Continue dragging
    OnDragRight(false, m_oldDragX, m_oldDragY, keys);
    OnDragRight(true, (double)x, (double)y, keys);
    m_oldDragX = x; m_oldDragY = y;
  }
  else if (event.RightUp() && !m_draggedShape && m_dragState == ContinueDraggingRight)
  {
    m_dragState = NoDragging;
    m_checkTolerance = true;

    OnDragRight(false, m_oldDragX, m_oldDragY, keys);
    OnEndDragRight((double)x, (double)y, keys);
    m_draggedShape = NULL;
  }

  // Non-dragging events
  else if (event.IsButton())
  {
    m_checkTolerance = true;

    // Find the nearest object
    int attachment = 0;
    wxShape *nearest_object = FindShape(x, y, &attachment);
    if (nearest_object) // Object event
    {
      if (event.LeftDown())
      {
        m_draggedShape = nearest_object;
        m_draggedAttachment = attachment;