Hello, I'm having a little problem with a view that I have, I'm using the resizeEvent of the QMainWindow the view is in to call a function that redraws the view with a grid, so far so good, when I resize the window the view resizes along and the grid to. I also have a QComboBox that I use to choose the scale of the grid squares, the currentIndexChanged SIGNAL of the comboBox triggers a slot that calls the function that redraws the grid, but the view only updates after I resize the window again, it was suppose to update the view with the new grid scale as soon as the user changed the comboBox...?

This is a simplified version of the original that I did to make it easier to see the portion of the program which contains the fault, I tested it and the same behavior shows here...

main.h:
Qt Code: 
  1. #include <QApplication>
  2. #include "maincontrol.h"
  3.  
  4. int main(int argc,char *argv[])
  5. {
  6.     QApplication a(argc,argv);
  7.     MainControl m;
  8.     m.show();
  9.     m.setted=1;
  10.     return a.exec();
  11. }
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maincontrol.h:
Qt Code: 
  1. #ifndef MAINCONTROL_H
  2. #define MAINCONTROL_H
  3.  
  4. #include <QMainWindow>
  5. #include <QGraphicsView>
  6. #include <QGraphicsScene>
  7. #include <QComboBox>
  8. #include <QPixmap>
  9. #include <QImage>
  10. #include <QResizeEvent>
  11. #include <QLayout>
  12. #include <QLabel>
  13.  
  14. class MainControl : public QMainWindow
  15. {
  16.     Q_OBJECT
  17. public:
  18.     explicit MainControl(QWidget *parent = 0);
  19.  
  20.     QHBoxLayout *combo_layout;
  21.     QHBoxLayout *view_layout;
  22.     QVBoxLayout *main_layout;
  23.     QWidget *central_widget;
  24.  
  25.     QGraphicsView *control_view;
  26.     QGraphicsScene *control_scene;
  27.     QPixmap *control_pixmap;
  28.     QComboBox *control_combobox;
  29.     QLabel *debug_label;
  30.     int SCALE;
  31.     int image_w;
  32.     int image_h;
  33.     int setted;
  34.     int set_pixel_value(int red,int green,int blue);
  35.     void process_canvas();
  36. protected:
  37.     void resizeEvent(QResizeEvent *e);
  38. signals:
  39.  
  40. public slots:
  41.     void update_scale(int s);
  42.  
  43. };
  44.  
  45. #endif // MAINCONTROL_H
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maincontrol.cpp:
Qt Code: 
  1. #include "maincontrol.h"
  2.  
  3. MainControl::MainControl(QWidget *parent) :
  4.     QMainWindow(parent)
  5. {
  6.     //----------------------initiate properties
  7.     SCALE=10;
  8.     image_w=300;
  9.     image_h=300;
  10.     setted=0;
  11.     control_scene=new QGraphicsScene;
  12.     control_view=new QGraphicsView(control_scene);
  13.     control_view->setMinimumSize(image_w,image_h);
  14.     control_view->setResizeAnchor(QGraphicsView::NoAnchor);
  15.     control_view->setAlignment(Qt::AlignLeft|Qt::AlignTop);
  16.  
  17.     control_pixmap=new QPixmap;
  18.     control_combobox=new QComboBox;
  19.  
  20.     QString c_str;
  21.     int cc=1;
  22.     while(cc<=10)
  23.     {
  24.     c_str.setNum(cc);
  25.     control_combobox->addItem(c_str);
  26.     cc++;
  27.     }
  28.     control_combobox->setCurrentIndex((SCALE/2)-1);
  29.  
  30.     combo_layout=new QHBoxLayout;
  31.     view_layout=new QHBoxLayout;
  32.     debug_label=new QLabel("");
  33.     main_layout=new QVBoxLayout;
  34.     central_widget=new QWidget;
  35.  
  36.     //----------------------set layouts
  37.     combo_layout->addWidget(control_combobox);
  38.     view_layout->addWidget(control_view);
  39.  
  40.     main_layout->addLayout(combo_layout);
  41.     main_layout->addLayout(view_layout);
  42.     main_layout->addWidget(debug_label);
  43.     central_widget->setLayout(main_layout);
  44.  
  45.     this->setCentralWidget(central_widget);
  46.  
  47.     //----------------------draw image once
  48.     process_canvas();
  49.     control_scene->addPixmap(*control_pixmap);
  50.     //----------------------connections
  51.     connect(control_combobox,SIGNAL(currentIndexChanged(int)),this,SLOT(update_scale(int)));
  52. }
  53. //--------------------------------------- PROCESS CANVAS -----------------------------------------------//
  54. //makes the image AND UPDATES it to the view
  55. //Problem:When resizeEvent calls this function it updates the view as it should according to
  56. //the it's last command (control_view->update()) but when update_scale calls it it doesn't update
  57. //until I resize it again
  58. void MainControl::process_canvas()
  59. {
  60.  QImage control_image(image_w,image_h,QImage::Format_RGB32);
  61.  control_image.fill(set_pixel_value(0,0,0));
  62.  int cy=0;
  63.  int cx=0;
  64.  while(cy<control_image.height())
  65.  {
  66.      while(cx<control_image.width())
  67.      {
  68.          if(cx%(10*SCALE)==0 || cy%(10*SCALE)==0)
  69.          {
  70.              control_image.setPixel(cx,cy,set_pixel_value(150,150,150));
  71.          }
  72.          cx++;
  73.      }
  74.      cx=0;
  75.      cy++;
  76.  }
  77.  control_pixmap->convertFromImage(control_image.scaled(image_w,image_h));
  78.  control_view->update();
  79. }
  80. //--------------------------------------- RESIZE EVENT -----------------------------------------------//
  81. //The size of the image was suppose to go along with the view
  82. void MainControl::resizeEvent(QResizeEvent *e)
  83. {
  84. if(setted)
  85. {
  86.     int new_w=e->size().width();
  87.     int old_w=e->oldSize().width();
  88.     int new_h=e->size().width();
  89.     int old_h=e->oldSize().width();
  90.  
  91.     image_w+=new_w-old_w;
  92.     image_h+=new_h-old_h;
  93.     process_canvas();
  94. }
  95. }
  96. //--------------------------------------- UPDATE SCALE -----------------------------------------------//
  97. //It is called when the user changes the value of the comboBox
  98. void MainControl::update_scale(int s)
  99. {
  100. SCALE=2*(s+1);
  101. process_canvas();
  102. }
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