added and documented wxApp::OnAssert

[wxWidgets.git] / src / common / dcbase.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        common/dcbase.cpp
// Purpose:     generic methods of the wxDC Class
// Author:      Vadim Zeitlin
// Modified by:
// Created:     05/25/99
// RCS-ID:      $Id$
// Copyright:   (c) wxWindows team
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

#ifdef __GNUG__
    #pragma implementation "dcbase.h"
#endif

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

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

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#include "wx/dc.h"

#include <math.h>

bool wxDCBase::sm_cacheing = FALSE;

// ============================================================================
// implementation
// ============================================================================

// ----------------------------------------------------------------------------
// special symbols
// ----------------------------------------------------------------------------

void wxDCBase::DoDrawCheckMark(wxCoord x1, wxCoord y1,
                               wxCoord width, wxCoord height)
{
    wxCHECK_RET( Ok(), wxT("invalid window dc") );

    wxCoord x2 = x1 + width,
            y2 = y1 + height;

    // this is to yield width of 3 for width == height == 10
    SetPen(wxPen(GetTextForeground(), (width + height + 1) / 7, wxSOLID));

    // we're drawing a scaled version of wx/generic/tick.xpm here
    wxCoord x3 = x1 + (4*width) / 10,   // x of the tick bottom
            y3 = y1 + height / 2;       // y of the left tick branch
    DoDrawLine(x1, y3, x3, y2);
    DoDrawLine(x3, y2, x2, y1);

    CalcBoundingBox(x1, y1);
    CalcBoundingBox(x2, y2);
}

// ----------------------------------------------------------------------------
// line/polygons
// ----------------------------------------------------------------------------

void wxDCBase::DrawLines(const wxList *list, wxCoord xoffset, wxCoord yoffset)
{
    int n = list->Number();
    wxPoint *points = new wxPoint[n];

    int i = 0;
    for ( wxNode *node = list->First(); node; node = node->Next(), i++ )
    {
        wxPoint *point = (wxPoint *)node->Data();
        points[i].x = point->x;
        points[i].y = point->y;
    }

    DoDrawLines(n, points, xoffset, yoffset);

    delete [] points;
}


void wxDCBase::DrawPolygon(const wxList *list,
                           wxCoord xoffset, wxCoord yoffset,
                           int fillStyle)
{
    int n = list->Number();
    wxPoint *points = new wxPoint[n];

    int i = 0;
    for ( wxNode *node = list->First(); node; node = node->Next(), i++ )
    {
        wxPoint *point = (wxPoint *)node->Data();
        points[i].x = point->x;
        points[i].y = point->y;
    }

    DoDrawPolygon(n, points, xoffset, yoffset, fillStyle);

    delete [] points;
}

// ----------------------------------------------------------------------------
// splines
// ----------------------------------------------------------------------------

#if wxUSE_SPLINES

// TODO: this API needs fixing (wxPointList, why (!const) "wxList *"?)
void wxDCBase::DrawSpline(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2, wxCoord x3, wxCoord y3)
{
    wxList point_list;

    wxPoint *point1 = new wxPoint;
    point1->x = x1; point1->y = y1;
    point_list.Append((wxObject*)point1);

    wxPoint *point2 = new wxPoint;
    point2->x = x2; point2->y = y2;
    point_list.Append((wxObject*)point2);

    wxPoint *point3 = new wxPoint;
    point3->x = x3; point3->y = y3;
    point_list.Append((wxObject*)point3);

    DrawSpline(&point_list);

    for( wxNode *node = point_list.First(); node; node = node->Next() )
    {
        wxPoint *p = (wxPoint *)node->Data();
        delete p;
    }
}

void wxDCBase::DrawSpline(int n, wxPoint points[])
{
    wxList list;
    for (int i =0; i < n; i++)
    {
        list.Append((wxObject*)&points[i]);
    }

    DrawSpline(&list);
}

// ----------------------------------- spline code ----------------------------------------

void wx_quadratic_spline(double a1, double b1, double a2, double b2,
                         double a3, double b3, double a4, double b4);
void wx_clear_stack();
int wx_spline_pop(double *x1, double *y1, double *x2, double *y2, double *x3,
        double *y3, double *x4, double *y4);
void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3,
          double x4, double y4);
static bool wx_spline_add_point(double x, double y);
static void wx_spline_draw_point_array(wxDCBase *dc);

wxList wx_spline_point_list;

#define                half(z1, z2)        ((z1+z2)/2.0)
#define                THRESHOLD        5

/* iterative version */

void wx_quadratic_spline(double a1, double b1, double a2, double b2, double a3, double b3, double a4,
                 double b4)
{
    register double  xmid, ymid;
    double           x1, y1, x2, y2, x3, y3, x4, y4;

    wx_clear_stack();
    wx_spline_push(a1, b1, a2, b2, a3, b3, a4, b4);

    while (wx_spline_pop(&x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)) {
        xmid = (double)half(x2, x3);
        ymid = (double)half(y2, y3);
        if (fabs(x1 - xmid) < THRESHOLD && fabs(y1 - ymid) < THRESHOLD &&
            fabs(xmid - x4) < THRESHOLD && fabs(ymid - y4) < THRESHOLD) {
            wx_spline_add_point( x1, y1 );
            wx_spline_add_point( xmid, ymid );
        } else {
            wx_spline_push(xmid, ymid, (double)half(xmid, x3), (double)half(ymid, y3),
                 (double)half(x3, x4), (double)half(y3, y4), x4, y4);
            wx_spline_push(x1, y1, (double)half(x1, x2), (double)half(y1, y2),
                 (double)half(x2, xmid), (double)half(y2, ymid), xmid, ymid);
        }
    }
}

/* utilities used by spline drawing routines */

typedef struct wx_spline_stack_struct {
    double           x1, y1, x2, y2, x3, y3, x4, y4;
} Stack;

#define         SPLINE_STACK_DEPTH             20
static Stack    wx_spline_stack[SPLINE_STACK_DEPTH];
static Stack   *wx_stack_top;
static int      wx_stack_count;

void wx_clear_stack()
{
    wx_stack_top = wx_spline_stack;
    wx_stack_count = 0;
}

void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4)
{
    wx_stack_top->x1 = x1;
    wx_stack_top->y1 = y1;
    wx_stack_top->x2 = x2;
    wx_stack_top->y2 = y2;
    wx_stack_top->x3 = x3;
    wx_stack_top->y3 = y3;
    wx_stack_top->x4 = x4;
    wx_stack_top->y4 = y4;
    wx_stack_top++;
    wx_stack_count++;
}

int wx_spline_pop(double *x1, double *y1, double *x2, double *y2,
                  double *x3, double *y3, double *x4, double *y4)
{
    if (wx_stack_count == 0)
        return (0);
    wx_stack_top--;
    wx_stack_count--;
    *x1 = wx_stack_top->x1;
    *y1 = wx_stack_top->y1;
    *x2 = wx_stack_top->x2;
    *y2 = wx_stack_top->y2;
    *x3 = wx_stack_top->x3;
    *y3 = wx_stack_top->y3;
    *x4 = wx_stack_top->x4;
    *y4 = wx_stack_top->y4;
    return (1);
}

static bool wx_spline_add_point(double x, double y)
{
  wxPoint *point = new wxPoint ;
  point->x = (int) x;
  point->y = (int) y;
  wx_spline_point_list.Append((wxObject*)point);
  return TRUE;
}

static void wx_spline_draw_point_array(wxDCBase *dc)
{
  dc->DrawLines(&wx_spline_point_list, 0, 0 );
  wxNode *node = wx_spline_point_list.First();
  while (node)
  {
    wxPoint *point = (wxPoint *)node->Data();
    delete point;
    delete node;
    node = wx_spline_point_list.First();
  }
}

void wxDCBase::DoDrawSpline( wxList *points )
{
    wxCHECK_RET( Ok(), wxT("invalid window dc") );

    wxPoint *p;
    double           cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4;
    double           x1, y1, x2, y2;

    wxNode *node = points->First();
    p = (wxPoint *)node->Data();

    x1 = p->x;
    y1 = p->y;

    node = node->Next();
    p = (wxPoint *)node->Data();

    x2 = p->x;
    y2 = p->y;
    cx1 = (double)((x1 + x2) / 2);
    cy1 = (double)((y1 + y2) / 2);
    cx2 = (double)((cx1 + x2) / 2);
    cy2 = (double)((cy1 + y2) / 2);

    wx_spline_add_point(x1, y1);

    while ((node = node->Next()) != NULL)
    {
        p = (wxPoint *)node->Data();
        x1 = x2;
        y1 = y2;
        x2 = p->x;
        y2 = p->y;
        cx4 = (double)(x1 + x2) / 2;
        cy4 = (double)(y1 + y2) / 2;
        cx3 = (double)(x1 + cx4) / 2;
        cy3 = (double)(y1 + cy4) / 2;

        wx_quadratic_spline(cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4);

        cx1 = cx4;
        cy1 = cy4;
        cx2 = (double)(cx1 + x2) / 2;
        cy2 = (double)(cy1 + y2) / 2;
    }

    wx_spline_add_point( cx1, cy1 );
    wx_spline_add_point( x2, y2 );

    wx_spline_draw_point_array( this );
}

#endif // wxUSE_SPLINES

// ----------------------------------------------------------------------------
// enhanced text drawing
// ----------------------------------------------------------------------------

void wxDCBase::GetMultiLineTextExtent(const wxString& text,
                                      wxCoord *x,
                                      wxCoord *y,
                                      wxCoord *h,
                                      wxFont *font)
{
    int widthTextMax = 0, widthLine,
        heightTextTotal = 0, heightLineDefault = 0, heightLine = 0;

    wxString curLine;
    for ( const wxChar *pc = text; ; pc++ )
    {
        if ( *pc == _T('\n') || *pc == _T('\0') )
        {
            if ( curLine.empty() )
            {
                // we can't use GetTextExtent - it will return 0 for both width
                // and height and an empty line should count in height
                // calculation

                // assume that this line has the same height as the previous
                // one
                if ( !heightLineDefault )
                    heightLineDefault = heightLine;

                if ( !heightLineDefault )
                {
                    // but we don't know it yet - choose something reasonable
                    GetTextExtent(_T("W"), NULL, &heightLineDefault,
                                  NULL, NULL, font);
                }

                heightTextTotal += heightLineDefault;
            }
            else
            {
                GetTextExtent(curLine, &widthLine, &heightLine,
                              NULL, NULL, font);
                if ( widthLine > widthTextMax )
                    widthTextMax = widthLine;
                heightTextTotal += heightLine;
            }

            if ( *pc == _T('\n') )
            {
               curLine.clear();
            }
            else
            {
               // the end of string
               break;
            }
        }
        else
        {
            curLine += *pc;
        }
    }

    if ( x )
        *x = widthTextMax;
    if ( y )
        *y = heightTextTotal;
    if ( h )
        *h = heightLine;
}

void wxDCBase::DrawLabel(const wxString& text,
                         const wxBitmap& bitmap,
                         const wxRect& rect,
                         int alignment,
                         int indexAccel,
                         wxRect *rectBounding)
{
    // find the text position
    wxCoord widthText, heightText, heightLine;
    GetMultiLineTextExtent(text, &widthText, &heightText, &heightLine);

    wxCoord width, height;
    if ( bitmap.Ok() )
    {
        width = widthText + bitmap.GetWidth();
        height = bitmap.GetHeight();
    }
    else // no bitmap
    {
        width = widthText;
        height = heightText;
    }

    wxCoord x, y;
    if ( alignment & wxALIGN_RIGHT )
    {
        x = rect.GetRight() - width;
    }
    else if ( alignment & wxALIGN_CENTRE_HORIZONTAL )
    {
        x = (rect.GetLeft() + rect.GetRight() + 1 - width) / 2;
    }
    else // alignment & wxALIGN_LEFT
    {
        x = rect.GetLeft();
    }

    if ( alignment & wxALIGN_BOTTOM )
    {
        y = rect.GetBottom() - height;
    }
    else if ( alignment & wxALIGN_CENTRE_VERTICAL )
    {
        y = (rect.GetTop() + rect.GetBottom() + 1 - height) / 2;
    }
    else // alignment & wxALIGN_TOP
    {
        y = rect.GetTop();
    }

    // draw the bitmap first
    wxCoord x0 = x,
            y0 = y,
            width0 = width;
    if ( bitmap.Ok() )
    {
        DrawBitmap(bitmap, x, y, TRUE /* use mask */);

        wxCoord offset = bitmap.GetWidth() + 4;
        x += offset;
        width -= offset;

        y += (height - heightText) / 2;
    }

    // we will draw the underscore under the accel char later
    wxCoord startUnderscore = 0,
            endUnderscore = 0,
            yUnderscore = 0;

    // split the string into lines and draw each of them separately
    wxString curLine;
    for ( const wxChar *pc = text; ; pc++ )
    {
        if ( *pc == _T('\n') || *pc == _T('\0') )
        {
            int xRealStart = x; // init it here to avoid compielr warnings

            if ( !curLine.empty() )
            {
                // NB: can't test for !(alignment & wxALIGN_LEFT) because
                //     wxALIGN_LEFT is 0
                if ( alignment & (wxALIGN_RIGHT | wxALIGN_CENTRE_HORIZONTAL) )
                {
                    wxCoord widthLine;
                    GetTextExtent(curLine, &widthLine, NULL);

                    if ( alignment & wxALIGN_RIGHT )
                    {
                        xRealStart += width - widthLine;
                    }
                    else // if ( alignment & wxALIGN_CENTRE_HORIZONTAL )
                    {
                        xRealStart += (width - widthLine) / 2;
                    }
                }
                //else: left aligned, nothing to do

                DrawText(curLine, xRealStart, y);
            }

            y += heightLine;

            // do we have underscore in this line? we can check yUnderscore
            // because it is set below to just y + heightLine if we do
            if ( y == yUnderscore )
            {
                // adjust the horz positions to account for the shift
                startUnderscore += xRealStart;
                endUnderscore += xRealStart;
            }

            if ( *pc == _T('\0') )
                break;

            curLine.clear();
        }
        else // not end of line
        {
            if ( pc - text.c_str() == indexAccel )
            {
                // remeber to draw underscore here
                GetTextExtent(curLine, &startUnderscore, NULL);
                curLine += *pc;
                GetTextExtent(curLine, &endUnderscore, NULL);

                yUnderscore = y + heightLine;
            }
            else
            {
                curLine += *pc;
            }
        }
    }

    // draw the underscore if found
    if ( startUnderscore != endUnderscore )
    {
        // it should be of the same colour as text
        SetPen(wxPen(GetTextForeground(), 0, wxSOLID));

        yUnderscore--;

        DrawLine(startUnderscore, yUnderscore, endUnderscore, yUnderscore);
    }

    // return bounding rect if requested
    if ( rectBounding )
    {
        *rectBounding = wxRect(x, y - heightText, widthText, heightText);
    }

    CalcBoundingBox(x0, y0);
    CalcBoundingBox(x0 + width0, y0 + height);
}