From 1c9ae095d60cff1b190dfd3cb161f71169d8e893 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ole-Andr=C3=A9=20Rodlie?= <ole.andre.rodlie@gmail.com>
Date: Sat, 19 Aug 2023 18:31:02 +0200
Subject: [PATCH] Better timeline UX

Scrolling on the timeline now supports modifiers CTRL and SHIFT.

* CTRL + wheel will now scale in/out the frame range as if you used the scrollbar
* SHIFT + wheel will now pan the frame range as if you used the scrollbar
* Without a modifier it works as before, scroll up/down

See https://github.com/orgs/friction2d/discussions/58#discussioncomment-6769336
---
 .../OptimalScrollArea/scrollarea.cpp          |  6 +++--
 src/app/GUI/animationwidgetscrollbar.cpp      | 25 +++++++++++++++++++
 src/app/GUI/animationwidgetscrollbar.h        |  2 ++
 src/app/GUI/timelinewidget.cpp                |  2 ++
 4 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/src/app/GUI/BoxesList/OptimalScrollArea/scrollarea.cpp b/src/app/GUI/BoxesList/OptimalScrollArea/scrollarea.cpp
index c55a3af37..2c328379b 100755
--- a/src/app/GUI/BoxesList/OptimalScrollArea/scrollarea.cpp
+++ b/src/app/GUI/BoxesList/OptimalScrollArea/scrollarea.cpp
@@ -58,8 +58,10 @@ void ScrollArea::resizeEvent(QResizeEvent *e) {
     QScrollArea::resizeEvent(e);
 }
 #include "GUI/global.h"
-void ScrollArea::callWheelEvent(QWheelEvent *event) {
-    if(event->angleDelta().y() > 0) {
+void ScrollArea::callWheelEvent(QWheelEvent *event)
+{
+    if (event->modifiers() & Qt::CTRL || event->modifiers() & Qt::SHIFT) { return; }
+    if (event->angleDelta().y() > 0) {
         scrollBy(0, -eSizesUI::widget);
     } else {
         scrollBy(0, eSizesUI::widget);
diff --git a/src/app/GUI/animationwidgetscrollbar.cpp b/src/app/GUI/animationwidgetscrollbar.cpp
index d3bfbb720..a57c0255a 100755
--- a/src/app/GUI/animationwidgetscrollbar.cpp
+++ b/src/app/GUI/animationwidgetscrollbar.cpp
@@ -304,6 +304,31 @@ void FrameScrollBar::setCanvasFrameRange(const FrameRange &range) {
     update();
 }
 
+void FrameScrollBar::callWheelEvent(QWheelEvent *event)
+{
+    if (!mRange) { return; }
+    bool triggered = false;
+    if (event->modifiers() & Qt::CTRL) {
+        int newFramesSpan = mViewedFramesSpan;
+        if (event->angleDelta().y() > 0) { newFramesSpan *= 0.85; }
+        else { newFramesSpan *= 1.15; }
+        setFramesSpan(newFramesSpan);
+        triggered = true;
+   } else if (event->modifiers() & Qt::SHIFT) {
+        if (event->angleDelta().y() > 0) {
+            setFirstViewedFrame(mFirstViewedFrame - mViewedFramesSpan/20);
+            triggered = true;
+        } else {
+            setFirstViewedFrame(mFirstViewedFrame + mViewedFramesSpan/20);
+            triggered = true;
+        }
+    }
+    if (!triggered) { return; }
+
+    emitTriggeredChange();
+    update();
+}
+
 void FrameScrollBar::emitChange() {
     emit frameRangeChange(getViewedRange());
 }
diff --git a/src/app/GUI/animationwidgetscrollbar.h b/src/app/GUI/animationwidgetscrollbar.h
index 7c161ac1d..283e1a6bb 100755
--- a/src/app/GUI/animationwidgetscrollbar.h
+++ b/src/app/GUI/animationwidgetscrollbar.h
@@ -59,6 +59,8 @@ class FrameScrollBar : public QWidget {
     void setDisplayedFrameRange(const FrameRange& range);
     void setViewedFrameRange(const FrameRange& range);
     void setCanvasFrameRange(const FrameRange& range);
+    void callWheelEvent(QWheelEvent *event);
+
 protected:
     qreal posToFrame(int xPos);
     void paintEvent(QPaintEvent *);
diff --git a/src/app/GUI/timelinewidget.cpp b/src/app/GUI/timelinewidget.cpp
index 0e0def452..5842bf7b5 100755
--- a/src/app/GUI/timelinewidget.cpp
+++ b/src/app/GUI/timelinewidget.cpp
@@ -284,6 +284,8 @@ TimelineWidget::TimelineWidget(Document &document,
 
     connect(mFrameRangeScrollBar, &FrameScrollBar::triggeredFrameRangeChange,
             this, &TimelineWidget::setViewedFrameRange);
+    connect(mKeysView, &KeysView::wheelEventSignal,
+            mFrameRangeScrollBar, &FrameScrollBar::callWheelEvent);
     mKeysViewLayout->addWidget(mFrameRangeScrollBar);
     //mSceneChooser->setCurrentScene(mDocument.fActiveScene); // why?