From 2a1838467a0511bde339c8a86613ed43317e4207 Mon Sep 17 00:00:00 2001
From: itsmattkc <itsmattkc@gmail.com>
Date: Fri, 15 Feb 2019 04:09:03 -0800
Subject: [PATCH] scrolling update

---
 panels/timeline.cpp   |  4 ++--
 panels/timeline.h     |  5 ++--
 ui/focusfilter.cpp    |  4 ++--
 ui/scrollarea.cpp     |  7 +++++-
 ui/timelinewidget.cpp | 53 +++++++++++++++++++++++++++++++------------
 5 files changed, 52 insertions(+), 21 deletions(-)

diff --git a/panels/timeline.cpp b/panels/timeline.cpp
index 3289a6866..7ba0a335c 100644
--- a/panels/timeline.cpp
+++ b/panels/timeline.cpp
@@ -752,11 +752,11 @@ QVector<int> Timeline::get_tracks_of_linked_clips(int i) {
 }
 
 void Timeline::zoom_in() {
-    multiply_zoom(true);
+    multiply_zoom(2.0);
 }
 
 void Timeline::zoom_out() {
-    multiply_zoom(false);
+    multiply_zoom(0.5);
 }
 
 bool is_clip_selected(Clip* clip, bool containing) {
diff --git a/panels/timeline.h b/panels/timeline.h
index 34aa9fea7..1270afbd9 100644
--- a/panels/timeline.h
+++ b/panels/timeline.h
@@ -232,9 +232,10 @@ public slots:
 
     void nest();
 
+    void zoom_in();
+    void zoom_out();
+
 private slots:
-	void zoom_in();
-	void zoom_out();
 	void snapping_clicked(bool checked);
 	void add_btn_click();
 	void add_menu_item(QAction*);
diff --git a/ui/focusfilter.cpp b/ui/focusfilter.cpp
index 6e5ffabca..7548ed82a 100644
--- a/ui/focusfilter.cpp
+++ b/ui/focusfilter.cpp
@@ -213,7 +213,7 @@ void FocusFilter::zoom_in() {
     } else if (focused_panel == panel_sequence_viewer) {
         panel_sequence_viewer->set_zoom(true);
     } else {
-        panel_timeline->multiply_zoom(true);
+        panel_timeline->zoom_in();
     }
 }
 
@@ -226,7 +226,7 @@ void FocusFilter::zoom_out() {
     } else if (focused_panel == panel_sequence_viewer) {
         panel_sequence_viewer->set_zoom(false);
     } else {
-        panel_timeline->multiply_zoom(false);
+        panel_timeline->zoom_out();
     }
 }
 
diff --git a/ui/scrollarea.cpp b/ui/scrollarea.cpp
index 7c9d6e90c..04b45407b 100644
--- a/ui/scrollarea.cpp
+++ b/ui/scrollarea.cpp
@@ -12,7 +12,12 @@ ScrollArea::ScrollArea(QWidget* parent) : QScrollArea(parent) {}
 void ScrollArea::wheelEvent(QWheelEvent *e) {
     if (config.scroll_zooms) {
         e->ignore();
-        if (e->angleDelta().y() != 0) panel_timeline->multiply_zoom(e->angleDelta().y() > 0);
+
+        if (e->angleDelta().y() > 0) {
+            panel_timeline->zoom_in();
+        } else if (e->angleDelta().y() < 0) {
+            panel_timeline->zoom_out();
+        }
     } else {
         QScrollArea::wheelEvent(e);
     }
diff --git a/ui/timelinewidget.cpp b/ui/timelinewidget.cpp
index 5beff5f23..cbbd6d9a7 100644
--- a/ui/timelinewidget.cpp
+++ b/ui/timelinewidget.cpp
@@ -341,21 +341,46 @@ void TimelineWidget::dragMoveEvent(QDragMoveEvent *event) {
 }
 
 void TimelineWidget::wheelEvent(QWheelEvent *event) {
-	bool alt = (event->modifiers() & Qt::AltModifier);
-	int scroll_amount = alt ? (event->angleDelta().x()) : (event->angleDelta().y());
-	if (scroll_amount != 0) {
-		bool shift = (event->modifiers() & Qt::ShiftModifier);
-		bool in = (scroll_amount > 0);
-		if (config.scroll_zooms != shift) {
-            panel_timeline->multiply_zoom(in);
-		} else {
-			QScrollBar* bar = alt ? scrollBar : panel_timeline->horizontalScrollBar;
+    // shift used to toggle zooming instead of scrolling
+    bool shift = (event->modifiers() & Qt::ShiftModifier);
 
-			int step = bar->singleStep();
-			if (in) step = -step;
-			bar->setValue(bar->value() + step);
-		}
-	}
+    if (!event->pixelDelta().isNull()) {
+        // if we got pixel scrolling data, prefer it over the angleDelta data
+
+        QScrollBar* horiz_bar = panel_timeline->horizontalScrollBar;
+        QScrollBar* vert_bar = scrollBar;
+
+        horiz_bar->setValue(horiz_bar->value() + event->pixelDelta().x());
+        vert_bar->setValue(vert_bar->value() + event->pixelDelta().y());
+
+    } else if (!event->angleDelta().isNull()) {
+
+        // alt is used to swap horizontal and vertical scrolling
+        bool alt = (event->modifiers() & Qt::AltModifier);
+
+        int scroll_amount = alt ? (event->angleDelta().x()) : (event->angleDelta().y());
+
+        bool in = (scroll_amount > 0);
+        if (config.scroll_zooms != shift) {
+
+            // if config.scroll_zooms is enabled or shift is held, zoom instead of scrolling
+            if (in) {
+                panel_timeline->multiply_zoom(1.5);
+            } else {
+                panel_timeline->multiply_zoom(0.75);
+            }
+
+        } else {
+            // pass the scrolling to the Timeline's main scrollbar for horizontal scrolling, or this widget's
+            // scrollbar for vertical scrolling
+
+            QScrollBar* bar = alt ? scrollBar : panel_timeline->horizontalScrollBar;
+
+            int step = bar->singleStep();
+            if (in) step = -step;
+            bar->setValue(bar->value() + step);
+        }
+    }
 }
 
 void TimelineWidget::dragLeaveEvent(QDragLeaveEvent* event) {