QT: "Download speed histogram" simulation implementation--thinking really good, can use their brains, even I have inspired (this idea seems to be universal)

I do not know which version of the Thunderbolt, there is a "download speed histogram" of the small interface, I prefer (but the latest version of the Thunderbolt is not), so decided to cottage one. Of course, this cottage can not download files, hehe.

Ideas:
1: Paint the background of the interface black
2: Generate a random number every 0.1 seconds and add them to a container

3: Overload the PaintEvent function, starting from the right side of the interface and sequentially drawing the elements in the container in reverse order (each data is a bar)

：

Code:

[CPP]View Plaincopyprint?

2. #include <QtGui>
4. #include <QtCore>
8. Class Barchart: Public qwidget
10. {
12. Q_object
14. Private
16. qlist<int> m_list; //Store the points recorded in the history
18. Qsize m_size; //size of the current drawing window
20. Qtimer M_timer; //timer, sends a signal every 0.1 seconds, simulates receiving data
22. Protected
24. void PaintEvent (Qpaintevent *event);
26. void Resizeevent (Qresizeevent *event);
28. Public
30. Barchart (Qwidget *parent = 0);
32. ~barchart () {}
34. Public Slots:
36. void Adddataslot ();
38. };
42. Barchart::barchart (Qwidget *parent)
44. : Qwidget (parent)
46. {
48. //define Timers
50. Qsrand (Qdatetime::currentdatetime (). Tomsecssinceepoch ());
52. Connect (&m_timer, SIGNAL (timeout ()), this , SLOT (Adddataslot ()));
54. M_timer.start (100);
56. }
60. void Barchart::p aintevent (qpaintevent *event)
62. {
64. const int WIDTH = 2;
66. qpainter painter (this);
68. //Set Background to black
70. Painter.setbrush (Qt::black);
72. Painter.drawrect ( -2,-2, M_size.width () +4, M_size.height () +4);
76. Painter.setpen (Qpen (Qt::green, WIDTH));
78. int TX, CX, CY1, Cy2;
80. tx = 0;
82. Cy1 = M_size.height ();
86. //Draw a vertical line of each section
88. qlist<Int>::iterator iter = M_list.end ();
90. While (iter! = M_list.begin ())
92. {
94. Cy2 = Cy1-(* (--iter) *m_size.height ()/1000);
96. CX = M_size.width ()-TX;
98. Painter.drawline (CX, Cy1, CX, cy2);
100. TX + = WIDTH;
102. }
106. }
110. void Barchart::resizeevent (Qresizeevent *event)
112. {
114. M_size = Event->size ();
116. Update ();
118. }
122. void Barchart::adddataslot ()
124. {
126. //Add a 0-999 of data
128. int temp = Qrand ()% 1000;
130. M_list.push_back (temp);
132. //If the data is too long, throw away the previous part
134. if (m_list.size () > M_size.width ())
136. M_list.pop_front ();
138. Update ();
140. }
144. #include "Main.moc"
148. int main (int argc, char **argv)
150. {
152. Qapplication app (argc, argv);
154. Barchart *bar = new Barchart;
156. Bar->show ();
158. return app.exec ();
160. }

http://blog.csdn.net/small_qch/article/details/7585758

QT: "Download speed histogram" simulation implementation--thinking really good, can use their brains, even I have inspired (this idea seems to be universal)