1 files changed, 158 insertions, 0 deletions
diff --git a/tools/build/v2/example/qt/qt4/hello/arrow.cpp b/tools/build/v2/example/qt/qt4/hello/arrow.cpp
new file mode 100644
index 0000000000..e821b16909
--- /dev/null
+++ b/tools/build/v2/example/qt/qt4/hello/arrow.cpp
@@ -0,0 +1,158 @@
+// Copyright Vladimir Prus 2005.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include "arrow.h"
+
+#include <QtGui/qapplication.h>
+
+#include <QtGui/qwidget.h>
+#include <QtGui/qpainter.h>
+#include <QtGui/qpainterpath.h>
+
+#include <stdlib.h>
+#include <math.h>
+
+Arrow_widget::Arrow_widget(QWidget* parent) : QWidget(parent), color_(0)
+{
+    QPalette pal = palette();
+    pal.setBrush(backgroundRole(), QBrush(Qt::white));
+    setPalette(pal);
+}
+
+void Arrow_widget::slotChangeColor()
+{
+    color_ = (color_ + 1) % 3;
+    update();
+}
+
+void 
+Arrow_widget::draw_arrow(int x1, int y1, int x2, int y2, QPainter& painter)
+{
+    // The length of the from the tip of the arrow to the point
+    // where line starts.
+    const int arrowhead_length = 16;
+    
+    QPainterPath arrow;
+    arrow.moveTo(x1, y1);
+    
+    // Determine the angle of the straight line.
+    double a1 = (x2-x1);
+    double a2 = (y2-y1);
+    double b1 = 1;
+    double b2 = 0;
+    
+    double straight_length = sqrt(a1*a1 + a2*a2);
+    
+    double dot_product = a1*b1 + a2*b2;
+    double cosine = dot_product/
+        (sqrt(pow(a1, 2) + pow(a2, 2))*sqrt(b1 + b2));
+    double angle = acos(cosine);
+    if (y1 < y2)
+    {
+        angle = -angle;
+    }
+    double straight_angle = angle*180/M_PI;
+    
+    double limit = 10;
+    
+    double angle_to_vertical;
+    if (fabs(straight_angle) < 90)
+        angle_to_vertical = fabs(straight_angle);
+    else if (straight_angle > 0)
+        angle_to_vertical = 180-straight_angle;
+    else
+        angle_to_vertical = 180-(-straight_angle);
+    
+    double angle_delta = 0;
+    if (angle_to_vertical > limit)
+        angle_delta = 30 * (angle_to_vertical - limit)/90;
+    double start_angle = straight_angle > 0 
+        ? straight_angle - angle_delta :
+        straight_angle + angle_delta;
+    
+    
+    QMatrix m1;
+    m1.translate(x1, y1);
+    m1.rotate(-start_angle);
+    
+    double end_angle = straight_angle > 0 
+        ? (straight_angle + 180 + angle_delta) :
+        (straight_angle + 180 - angle_delta);
+    
+    QMatrix m2;
+    m2.reset();
+    m2.translate(x2, y2);        
+    m2.rotate(-end_angle);
+    
+    arrow.cubicTo(m1.map(QPointF(straight_length/2, 0)),              
+                  m2.map(QPointF(straight_length/2, 0)),
+                  m2.map(QPointF(arrowhead_length, 0)));
+    
+    painter.save();
+    painter.setBrush(Qt::NoBrush);
+    painter.drawPath(arrow);    
+    painter.restore();
+    
+    painter.save();
+    painter.translate(x2, y2);
+    
+    painter.rotate(-90);
+    painter.rotate(-end_angle);
+    painter.rotate(180);
+    
+    QPolygon arrowhead(4);
+    arrowhead.setPoint(0, 0, 0);
+    arrowhead.setPoint(1, arrowhead_length/3, -arrowhead_length*5/4);
+    arrowhead.setPoint(2, 0, -arrowhead_length);
+    arrowhead.setPoint(3, -arrowhead_length/3, -arrowhead_length*5/4);
+    
+    painter.drawPolygon(arrowhead);
+    
+    painter.restore();            
+    
+}
+
+
+void Arrow_widget::paintEvent(QPaintEvent*)
+{
+    QPainter p(this);
+    
+    p.setRenderHint(QPainter::Antialiasing);
+    
+    int base_x = 550;
+    int base_y = 200;
+
+    if (color_ == 0)   
+        p.setBrush(Qt::black);
+    else if (color_ == 1)
+        p.setBrush(Qt::green);
+    else if (color_ == 2)
+        p.setBrush(Qt::yellow);
+    else
+        p.setBrush(Qt::black);
+    
+    for (int x_step = 0; x_step < 6; ++x_step)
+    {
+        for (int y_step = 1; y_step <= 3; ++y_step)
+        {
+            draw_arrow(base_x, base_y, base_x+x_step*100, 
+                       base_y - y_step*50, p);
+            
+            draw_arrow(base_x, base_y, base_x+x_step*100, 
+                       base_y + y_step*50, p);
+            
+            draw_arrow(base_x, base_y, base_x-x_step*100, 
+                       base_y + y_step*50, p);
+            
+            draw_arrow(base_x, base_y, base_x-x_step*100, 
+                       base_y - y_step*50, p);
+        }
+    }
+
+    draw_arrow(50, 400, 1000, 450, p);
+    draw_arrow(1000, 400, 50, 450, p);
+    
+}
+