How to find out the type of the clicked item..

[Kapil]

still gives error and this is what it says..

[HTML]

error: no match for 'operator==' in '(((QList<Q3CanvasItem*>*)
((ImageDraw*)this)) + 56u)->QList<T>::at [with T = Q3CanvasItem*](i) == Q3ValueL
ist<T>::at(typename QLinkedList<T>::size_type) [with T = Q3CanvasItem*](i)'

[/HTML]

[munna]

Can you paste your code ?

[Kapil]

Yaa..

Here is the code:

CanvasMouse.cpp This file handles the mouse click events and then finds the point through the collision method and sends the info to the ImageDraw class..

#include "canvasmouse.h"
CanvasMouse::CanvasMouse(Q3Canvas *pCanvas, QFrame *frame): Q3CanvasView(frame)
{
    m_pCanvas = pCanvas;
    Q3CanvasView::setCanvas(m_pCanvas);
    m_pCanvas->setBackgroundColor(Qt::white);
    m_pCanvas->resize(400, 400);
    imgdraw = new ImageDraw(m_pCanvas);
    setDraw = false;
    startDraw = false;
 
}
 
CanvasMouse::~CanvasMouse()
{
}
 
void CanvasMouse::contentsMousePressEvent(QMouseEvent* e)
{
    if(setDraw)
    {
               if(e->button() == Qt::LeftButton)
               {
                    pPress = inverseWorldMatrix().map(e->pos());
                    startDraw = true;
               }
    }
 
}
void CanvasMouse::contentsMouseReleaseEvent(QMouseEvent* e)
{
 
     if(setDraw)
     {
         if((e->button() == Qt::LeftButton) && startDraw)
         {
            pRelease = inverseWorldMatrix().map(e->pos());
            Q3CanvasItemList l = m_pCanvas->collisions(pRelease);;
 
            imgdraw->selectLine(l);
         }
     }
}

#include "canvasmouse.h"
CanvasMouse::CanvasMouse(Q3Canvas *pCanvas, QFrame *frame): Q3CanvasView(frame)
{
    m_pCanvas = pCanvas;
    Q3CanvasView::setCanvas(m_pCanvas);
    m_pCanvas->setBackgroundColor(Qt::white);
    m_pCanvas->resize(400, 400);
    imgdraw = new ImageDraw(m_pCanvas);
    setDraw = false;
    startDraw = false;
    
}

CanvasMouse::~CanvasMouse()
{
}

void CanvasMouse::contentsMousePressEvent(QMouseEvent* e)
{
    if(setDraw)
    {
               if(e->button() == Qt::LeftButton)
               {
                    pPress = inverseWorldMatrix().map(e->pos());
                    startDraw = true;
               }
    }
    
}
void CanvasMouse::contentsMouseReleaseEvent(QMouseEvent* e)
{
     
     if(setDraw)
     {
         if((e->button() == Qt::LeftButton) && startDraw)
         {
            pRelease = inverseWorldMatrix().map(e->pos());
            Q3CanvasItemList l = m_pCanvas->collisions(pRelease);;

            imgdraw->selectLine(l);
         }
     }
}

To copy to clipboard, switch view to plain text mode 

[B]ImageDraw.cpp [B]: This class does the finding of the line number and rect number. Its the selectLine function that finds the line number.

#include "imagedraw.h"
#include <Q3ValueList>
 
ImageDraw::ImageDraw(Q3Canvas *pCanvas): m_pCanvas(pCanvas)
{
    drawLine();
    drawRectangle();
}
ImageDraw::~ImageDraw()
{
}
void ImageDraw::drawLine()
{
     int i;
     int xxPoint = 2,xyPoint = 2,yxPoint = 202,yyPoint = 2;
     lineNum = 20;
     m_pCanvasLine = new Q3CanvasLine*[lineNum];
     for(i=0;i<lineNum;i++)
     {
          xyPoint = (i+1)*4;
          yyPoint = xyPoint;
          m_pCanvasLine[i] = new Q3CanvasLine(m_pCanvas);
          m_pCanvasLine[i]->setPoints(xxPoint,xyPoint,yxPoint,yyPoint);
          m_pCanvasLine[i]->show();          
 
     }
 
     m_pLineItem = new Q3CanvasLine(m_pCanvas);
     lineList.append(m_pLineItem);
 
}
 
void ImageDraw::drawRectangle()
{
     int xPoint = 4, yPoint = 100;
     int height = 50, width = 80;
     int i;
     recNum = 5;
     m_pCanvasRectangle = new Q3CanvasRectangle*[recNum];
     for(i=0;i<recNum;i++)
     {
         m_pCanvasRectangle[i] = new Q3CanvasRectangle(xPoint, yPoint, width, height, m_pCanvas);
         m_pCanvasRectangle[i]->show();
         yPoint += 75;
     }
 
} 
 
void ImageDraw::selectLine(Q3CanvasItemList item)
{
     int i=0;
     m_itemLine = item;
     for (Q3CanvasItemList::Iterator it= m_itemLine.begin(); it!= m_itemLine.end(); ++it) 
     {
       if ( (*it)->rtti() == 7 )
       {
          for(i=0;i<lineList.size();i++)
          {
              if(lineList.at(i) == m_itemLine.at(i))
              { 
 
              QMessageBox::information(this, tr("Mouse Event"),tr("Line %1 Mouse Event Handled ").arg(i)); 
 
              }
 
           }
       }
       else if ( (*it)->rtti() == 5 )
       {
           QMessageBox::information(this, tr("Mouse Event"),tr("Rectangle Mouse Event Handled ")); 
       }
     }   
}

#include "imagedraw.h"
#include <Q3ValueList>

ImageDraw::ImageDraw(Q3Canvas *pCanvas): m_pCanvas(pCanvas)
{
    drawLine();
    drawRectangle();
}
ImageDraw::~ImageDraw()
{
}
void ImageDraw::drawLine()
{
     int i;
     int xxPoint = 2,xyPoint = 2,yxPoint = 202,yyPoint = 2;
     lineNum = 20;
     m_pCanvasLine = new Q3CanvasLine*[lineNum];
     for(i=0;i<lineNum;i++)
     {
          xyPoint = (i+1)*4;
          yyPoint = xyPoint;
          m_pCanvasLine[i] = new Q3CanvasLine(m_pCanvas);
          m_pCanvasLine[i]->setPoints(xxPoint,xyPoint,yxPoint,yyPoint);
          m_pCanvasLine[i]->show();          
                   
     }
     
     m_pLineItem = new Q3CanvasLine(m_pCanvas);
     lineList.append(m_pLineItem);
     
}

void ImageDraw::drawRectangle()
{
     int xPoint = 4, yPoint = 100;
     int height = 50, width = 80;
     int i;
     recNum = 5;
     m_pCanvasRectangle = new Q3CanvasRectangle*[recNum];
     for(i=0;i<recNum;i++)
     {
         m_pCanvasRectangle[i] = new Q3CanvasRectangle(xPoint, yPoint, width, height, m_pCanvas);
         m_pCanvasRectangle[i]->show();
         yPoint += 75;
     }
     
} 

void ImageDraw::selectLine(Q3CanvasItemList item)
{
     int i=0;
     m_itemLine = item;
     for (Q3CanvasItemList::Iterator it= m_itemLine.begin(); it!= m_itemLine.end(); ++it) 
     {
       if ( (*it)->rtti() == 7 )
       {
          for(i=0;i<lineList.size();i++)
          {
              if(lineList.at(i) == m_itemLine.at(i))
              { 
                
              QMessageBox::information(this, tr("Mouse Event"),tr("Line %1 Mouse Event Handled ").arg(i)); 
             
              }
           
           }
       }
       else if ( (*it)->rtti() == 5 )
       {
           QMessageBox::information(this, tr("Mouse Event"),tr("Rectangle Mouse Event Handled ")); 
       }
     }   
}

To copy to clipboard, switch view to plain text mode 

ImageDraw.h: The header file where i have made the dec.

#ifndef IMAGEDRAW_H
#define IMAGEDRAW_H
 
#include <QtGui>
#include <Q3Canvas>
#include <qdir.h>
#include <QColor>
#include <Q3CanvasLine>
#include <qevent.h>
#include <QPoint>
#include <Q3CanvasView>
#include <Q3ScrollView>
#include <Q3CanvasItem>
#include <Q3CanvasItemList>
#include <QPen>
#include <QList>
 
class ImageDraw : public Q3CanvasView
{
      public:
             ImageDraw(Q3Canvas *pCanvas);
             ~ImageDraw();
             void drawLine();
             void drawRectangle();
             void selectLine(Q3CanvasItemList item);
             //void selectRect(Q3CanvasItemList item);             
 
      private:
              Q3Canvas *m_pCanvas;
              Q3CanvasLine **m_pCanvasLine;
              Q3CanvasRectangle **m_pCanvasRectangle;
              Q3CanvasItemList m_itemLine;
              Q3CanvasItemList m_itemRect;
              QList<Q3CanvasItem *> lineList;
              Q3CanvasItem *m_pLineItem;
              //const QPoint m_pointLine,m_pointRect;
              int lineNum;
              int recNum;
              bool lineDraw,rectDraw;
};
 
#endif

#ifndef IMAGEDRAW_H
#define IMAGEDRAW_H

#include <QtGui>
#include <Q3Canvas>
#include <qdir.h>
#include <QColor>
#include <Q3CanvasLine>
#include <qevent.h>
#include <QPoint>
#include <Q3CanvasView>
#include <Q3ScrollView>
#include <Q3CanvasItem>
#include <Q3CanvasItemList>
#include <QPen>
#include <QList>

class ImageDraw : public Q3CanvasView
{
      public:
             ImageDraw(Q3Canvas *pCanvas);
             ~ImageDraw();
             void drawLine();
             void drawRectangle();
             void selectLine(Q3CanvasItemList item);
             //void selectRect(Q3CanvasItemList item);             
      
      private:
              Q3Canvas *m_pCanvas;
              Q3CanvasLine **m_pCanvasLine;
              Q3CanvasRectangle **m_pCanvasRectangle;
              Q3CanvasItemList m_itemLine;
              Q3CanvasItemList m_itemRect;
              QList<Q3CanvasItem *> lineList;
              Q3CanvasItem *m_pLineItem;
              //const QPoint m_pointLine,m_pointRect;
              int lineNum;
              int recNum;
              bool lineDraw,rectDraw;
};

#endif

To copy to clipboard, switch view to plain text mode 

Please tell me what can be the problem...

[Kapil]

Hi munna...

Thanks a lot for ur suggestions..

I used the function collidesWith(lineList.at(i)) and it gave me the value of the line i have clicked on...

Also i was able to create the lineList ..

One doubt... How can I colour the created line with some other colour..

Using the pen, we create a line with another coloue but is there any function like stColour for the line which could set the lines colour to the one i need..

Thanking you,
Kapil

[munna]

Please Explain the following lines.

m_pCanvasLine = new Q3CanvasLine*[lineNum];
for(i=0;i<lineNum;i++) {
          xyPoint = (i+1)*4;
          yyPoint = xyPoint;
          m_pCanvasLine[i] = new Q3CanvasLine(m_pCanvas);
          m_pCanvasLine[i]->setPoints(xxPoint,xyPoint,yxPoint,yyPoint);
          m_pCanvasLine[i]->show();
}
m_pLineItem = new Q3CanvasLine(m_pCanvas);
lineList.append(m_pLineItem);

m_pCanvasLine = new Q3CanvasLine*[lineNum];
for(i=0;i<lineNum;i++) {
          xyPoint = (i+1)*4;
          yyPoint = xyPoint;
          m_pCanvasLine[i] = new Q3CanvasLine(m_pCanvas);
          m_pCanvasLine[i]->setPoints(xxPoint,xyPoint,yxPoint,yyPoint);
          m_pCanvasLine[i]->show();
}
m_pLineItem = new Q3CanvasLine(m_pCanvas);
lineList.append(m_pLineItem);

To copy to clipboard, switch view to plain text mode 

and

m_pCanvasRectangle = new Q3CanvasRectangle*[recNum];
for(i=0;i<recNum;i++){
     m_pCanvasRectangle[i] = new Q3CanvasRectangle(xPoint, yPoint, width, height, _pCanvas);
     m_pCanvasRectangle[i]->show();
     yPoint += 75;
}

m_pCanvasRectangle = new Q3CanvasRectangle*[recNum];
for(i=0;i<recNum;i++){
     m_pCanvasRectangle[i] = new Q3CanvasRectangle(xPoint, yPoint, width, height, _pCanvas);
     m_pCanvasRectangle[i]->show();
     yPoint += 75;
}

To copy to clipboard, switch view to plain text mode 

As i said earlier you dont need to maintain two lists. One list should be more than enough to achieve your task. Please try to find out what exactly you need to achieve and what you are doing in your code.

[Kapil]

Please Explain the following lines.

m_pCanvasLine = new Q3CanvasLine*[lineNum];
for(i=0;i<lineNum;i++) {
          xyPoint = (i+1)*4;
          yyPoint = xyPoint;
          m_pCanvasLine[i] = new Q3CanvasLine(m_pCanvas);
          m_pCanvasLine[i]->setPoints(xxPoint,xyPoint,yxPoint,yyPoint);
          m_pCanvasLine[i]->show();
}
m_pLineItem = new Q3CanvasLine(m_pCanvas);
lineList.append(m_pLineItem);

m_pCanvasLine = new Q3CanvasLine*[lineNum];
for(i=0;i<lineNum;i++) {
          xyPoint = (i+1)*4;
          yyPoint = xyPoint;
          m_pCanvasLine[i] = new Q3CanvasLine(m_pCanvas);
          m_pCanvasLine[i]->setPoints(xxPoint,xyPoint,yxPoint,yyPoint);
          m_pCanvasLine[i]->show();
}
m_pLineItem = new Q3CanvasLine(m_pCanvas);
lineList.append(m_pLineItem);

To copy to clipboard, switch view to plain text mode 

and

m_pCanvasRectangle = new Q3CanvasRectangle*[recNum];
for(i=0;i<recNum;i++){
     m_pCanvasRectangle[i] = new Q3CanvasRectangle(xPoint, yPoint, width, height, _pCanvas);
     m_pCanvasRectangle[i]->show();
     yPoint += 75;
}

m_pCanvasRectangle = new Q3CanvasRectangle*[recNum];
for(i=0;i<recNum;i++){
     m_pCanvasRectangle[i] = new Q3CanvasRectangle(xPoint, yPoint, width, height, _pCanvas);
     m_pCanvasRectangle[i]->show();
     yPoint += 75;
}

To copy to clipboard, switch view to plain text mode 

As i said earlier you dont need to maintain two lists. One list should be more than enough to achieve your task. Please try to find out what exactly you need to achieve and what you are doing in your code.

Hi.. yaa i understood it.. i was doing this mistake.. i after that removed the array and just maintained the QList as you had told me too.. also i was able to view the line number as i told in the reply just above ur last reply...

Thanks a lot for ur help..

Please tell me that is there any setColour sort of function for chaging the line or rectangle colour on click.. or i have to set a pen and recreate the line or rect over the created line...

Thanks again...

Kapil