[Performous-commit] Tapio Vierros : Zooming now maintains the viewport position.

[Tapio V. <aa...@us...>]

Module: editor
Branch: master
Commit: 388fe6dd8e930a4e806c1b21d61642c1d151613e

Author: Tapio Vierros <tap...@gm...>
Date:   Tue Feb  8 10:44:32 2011 +0200

Zooming now maintains the viewport position.

---

 notegraphwidget.cc  |    6 +++---
 notelabelmanager.cc |   35 ++++++++++++++++++++++++++++++++---
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/notegraphwidget.cc b/notegraphwidget.cc
index a616f24..b3b0e90 100644
--- a/notegraphwidget.cc
+++ b/notegraphwidget.cc
@@ -334,8 +334,8 @@ void NoteGraphWidget::wheelEvent(QWheelEvent *event)
 {
 	// Ctrl + Wheel = Zoom
 	if (event->modifiers() & Qt::ControlModifier && event->orientation() == Qt::Vertical) {
-		float numDegrees = event->delta() / 8;
-		float numSteps = numDegrees / 15;
+		float numDegrees = event->delta() / 8; // Qt resolution is 8th of a degree
+		float numSteps = numDegrees / 15; // Usually mice have 15 degree steps
 		zoom(numSteps);
 		event->accept();
 		return;
@@ -531,7 +531,7 @@ void SeekHandle::moveEvent(QMoveEvent*)
 			QScrollBar *scrollVer = scrollArea->verticalScrollBar();
 			int y = 0;
 			if (scrollVer) y = scrollVer->value();
-				scrollArea->ensureVisible(x() + scrollArea->width()/3, y, scrollArea->width()/3, 0);
+			scrollArea->ensureVisible(x() + scrollArea->width()/3, y, scrollArea->width()/3, 0);
 		}
 	}
 }
diff --git a/notelabelmanager.cc b/notelabelmanager.cc
index 79ae309..d23ee67 100644
--- a/notelabelmanager.cc
+++ b/notelabelmanager.cc
@@ -2,6 +2,8 @@
 #include <QString>
 #include <QInputDialog>
 #include <QLineEdit>
+#include <QScrollArea>
+#include <QScrollBar>
 #include "notegraphwidget.hh"
 #include "notelabel.hh"
 #include "operation.hh"
@@ -244,15 +246,42 @@ void NoteLabelManager::doOperation(const Operation& op, Operation::OperationFlag
 }
 
 void NoteLabelManager::zoom(float steps) {
-	m_pixelsPerSecond += steps * 20;
-	if (m_pixelsPerSecond < 100) m_pixelsPerSecond = 100;
-	else if (m_pixelsPerSecond > 300) m_pixelsPerSecond = 300;
+	// Limits
+	const float ppsstep = 20.0f;
+	const float minpps = 100;
+	const float maxpps = 300;
+	if (m_pixelsPerSecond <= minpps && steps < 0) return;
+	else if (m_pixelsPerSecond >= maxpps && steps > 0) return;
+
+	// Get scrollArea position
+	QScrollArea *scrollArea = NULL;
+	double scrollSecs = -1;
+	if (parentWidget()) {
+		scrollArea = qobject_cast<QScrollArea*>(parentWidget()->parent());
+		if (scrollArea) scrollSecs = px2s(scrollArea->horizontalScrollBar()->value() + scrollArea->width()/2);
+	}
+
+	// Update zoom factor
+	m_pixelsPerSecond += steps * ppsstep;
+	if (m_pixelsPerSecond < minpps) m_pixelsPerSecond = minpps;
+	else if (m_pixelsPerSecond > maxpps) m_pixelsPerSecond = maxpps;
+
+	// Update scroll bar position
+	if (scrollArea && scrollSecs >= 0) {
+		QScrollBar *scrollVer = scrollArea->verticalScrollBar();
+		int y = 0;
+		if (scrollVer) y = scrollVer->value();
+		scrollArea->ensureVisible(s2px(scrollSecs), y, scrollArea->width()/2, 0);
+		std::cout << "YEAH" << std::endl;
+	}
 
+	// Update notes
 	for (int i = 0; i < m_notes.size(); ++i) {
 		const Note &n = m_notes[i]->note();
 		m_notes[i]->setGeometry(s2px(n.begin), m_notes[i]->y(), s2px(n.length()), m_notes[i]->height());
 	}
 
+	// Update pitch visualization
 	update();
 	std::cout << "pixPerSec: " << m_pixelsPerSecond << std::endl;
 }