Merge lp:~mixxxdevelopers/mixxx/features_knobs into lp:~mixxxdevelopers/mixxx/trunk

[William Good]

Provides various enhancements to the knob widget.

1. Hides mouse cursor and captures mouse input on left-mouse-down on a wknob. Cursor re-appears where mouse-down occurred on mouse-up.
2. Knobs can now be turned by both vertical and horizontal (new) movement.

Both effectively fix bug 767409, and should give a much nicer interface to Mixxx controls represented by wknob.

[William Good (bkgood)]

Confirmed working on Windows, jus tested successfully on osx, RJ and I both tested on Linux/X11. Merging as per https://bugs.launchpad.net/mixxx/+bug/767409/comments/11 .

review: Approve

=== modified file 'mixxx/src/widget/wknob.cpp'
--- mixxx/src/widget/wknob.cpp	2010-11-01 05:12:23 +0000
+++ mixxx/src/widget/wknob.cpp	2011-05-03 03:28:26 +0000
@@ -116,8 +116,21 @@
 void WKnob::mouseMoveEvent(QMouseEvent * e)
 {
     if (!m_bRightButtonPressed) {
-        m_fValue += (m_dStartValue-e->y());
-        m_dStartValue = e->y();
+        QPoint cur(e->globalPos());
+        QPoint diff(cur - m_startPos);
+        double dist = sqrt(static_cast<double>(diff.x() * diff.x() + diff.y() * diff.y()));
+        bool y_dominant = abs(diff.y()) > abs(diff.x());
+
+        // if y is dominant, then thread an increase in dy as negative (y is
+        // pointed downward). Otherwise, if y is not dominant and x has
+        // decreased, then thread it as negative.
+        if ((y_dominant && diff.y() > 0) || (!y_dominant && diff.x() < 0)) {
+            dist = -dist;
+        }
+
+        m_fValue += dist;
+        QCursor::setPos(m_startPos);
+
         if (m_fValue>127.)
             m_fValue = 127.;
         else if (m_fValue<0.)
@@ -129,29 +142,34 @@
 
 void WKnob::mousePressEvent(QMouseEvent * e)
 {
-    m_dStartValue = e->y();
+    m_startPos = e->globalPos();
 
     if (e->button() == Qt::RightButton)
     {
         reset();
         m_bRightButtonPressed = true;
+    } else {
+        QApplication::setOverrideCursor(Qt::BlankCursor);
     }
 }
 
 void WKnob::mouseReleaseEvent(QMouseEvent * e)
 {
-    if (e->button()==Qt::LeftButton)
+    if (e->button() == Qt::LeftButton) {
+        QCursor::setPos(m_startPos);
+        QApplication::restoreOverrideCursor();
         emit(valueChangedLeftUp(m_fValue));
-    else if (e->button()==Qt::RightButton)
+    } else if (e->button()==Qt::RightButton) {
         m_bRightButtonPressed = false;
         //emit(valueChangedRightUp(m_fValue));
+    }
 
     update();
 }
 
 void WKnob::wheelEvent(QWheelEvent *e)
 {
-    double wheelDirection = ((QWheelEvent *)e)->delta() / 120.;
+    double wheelDirection = ((QWheelEvent *)e)->delta() / 120.;
     double newValue = getValue() + (wheelDirection);
     this->updateValue(newValue);
 

=== modified file 'mixxx/src/widget/wknob.h'
--- mixxx/src/widget/wknob.h	2010-07-11 05:46:55 +0000
+++ mixxx/src/widget/wknob.h	2011-05-03 03:28:26 +0000
@@ -57,8 +57,8 @@
     QPixmap **m_pPixmaps;
     /** Associated background pixmap */
     QPixmap *m_pPixmapBack;
-    /** Values used when pressing mouse */
-    double m_dStartValue;
+    /** Starting point when left mouse button is pressed */
+    QPoint m_startPos;
     /** True if disabled pixmaps is loaded */
     bool m_bDisabledLoaded;
 };