Fix Minor Bug with Zoom Timeline to Fit

As reported here: https://forum.shotcut.org/t/minor-bug-with-zoom-timeline-to-fit/38270 Perform the zoom twice (separated by a timer delay) to get the zoom correct.
mltframework · Aug 11, 2023 · 2df1292 · 2df1292 · ddennedy · Sep 12, 2023
1 parent bd62f33
commit 2df1292
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Showing 2 changed files with 44 additions and 8 deletions.
diff --git a/src/qml/views/keyframes/keyframes.qml b/src/qml/views/keyframes/keyframes.qml
@@ -70,12 +70,6 @@ Rectangle {
         adjustZoom(-0.0625);
     }
 
-    function zoomToFit() {
-        setZoom(Math.pow((tracksFlickable.width - 50) * timeScale / tracksContainer.width - 0.01, 1 / 3));
-        scrollZoomTimer.stop();
-        tracksFlickable.contentX = 0;
-    }
-
     function resetZoom() {
         setZoom(1);
     }
@@ -97,6 +91,26 @@ Rectangle {
         }
     }
 
+    Timer {
+        id: zoomToFitTimer
+
+        property var loopCount: 0
+        interval: 1
+        repeat: true
+        function startZoomFit() {
+            loopCount = 0;
+            start();
+        }
+        onTriggered: {
+            setZoom(Math.pow((tracksFlickable.width - 50) * timeScale / tracksContainer.width - 0.01, 1 / 3));
+            loopCount++;
+            // Due to rounding errors, sometimes the zoom needs to be calculated twice to get it right.
+            if (loopCount >= 2) {
+                stop();
+            }
+        }
+    }
+
     MouseArea {
         anchors.fill: parent
         acceptedButtons: Qt.RightButton
@@ -608,7 +622,9 @@ Rectangle {
         }
 
         function onZoomToFit() {
-            zoomToFit();
+            scrollZoomTimer.stop();
+            tracksFlickable.contentX = 0;
+            zoomToFitTimer.startZoomFit();
         }
 
         function onResetZoom() {

diff --git a/src/qml/views/timeline/timeline.qml b/src/qml/views/timeline/timeline.qml
@@ -96,6 +96,26 @@ Rectangle {
         }
     }
 
+    Timer {
+        id: zoomToFitTimer
+
+        property var loopCount: 0
+        interval: 1
+        repeat: true
+        function startZoomFit() {
+            loopCount = 0;
+            start();
+        }
+        onTriggered: {
+            setZoom(Math.pow((tracksFlickable.width - 50) * multitrack.scaleFactor / tracksContainer.width - 0.01, 1 / 3));
+            loopCount++;
+            // Due to rounding errors, sometimes the zoom needs to be calculated twice to get it right.
+            if (loopCount >= 2) {
+                stop();
+            }
+        }
+    }
+
     MouseArea {
         anchors.fill: parent
         acceptedButtons: Qt.RightButton
@@ -807,9 +827,9 @@ Rectangle {
         }
 
         function onZoomToFit() {
-            setZoom(Math.pow((tracksFlickable.width - 50) * multitrack.scaleFactor / tracksContainer.width - 0.01, 1 / 3));
             scrollZoomTimer.stop();
             tracksFlickable.contentX = 0;
+            zoomToFitTimer.startZoomFit();
         }
 
         function onSetZoom(value) {