From 1555dc2296cbdc77797aa2f86cab8eaba5c913b1 Mon Sep 17 00:00:00 2001 From: Lasath Fernando Date: Tue, 28 Apr 2020 00:29:51 -0700 Subject: [PATCH] Shamelessly steal `ScrollHelper.qml` from spectral I mean, we're both GPL so... :P --- resources/qml/ScrollHelper.qml | 108 +++++++++++++++++++++++++++++++++ resources/qml/TimelineView.qml | 17 ++---- resources/res.qrc | 1 + 3 files changed, 113 insertions(+), 13 deletions(-) create mode 100644 resources/qml/ScrollHelper.qml diff --git a/resources/qml/ScrollHelper.qml b/resources/qml/ScrollHelper.qml new file mode 100644 index 00000000..669d9608 --- /dev/null +++ b/resources/qml/ScrollHelper.qml @@ -0,0 +1,108 @@ +/* + * Copyright (C) 2016 Michael Bohlender, + * Copyright (C) 2017 Christian Mollekopf, + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +import QtQuick 2.12 +import QtQuick.Controls 2.12 + +/* +* Shamelessly stolen from: +* https://gitlab.com/spectral-im/spectral/-/blob/master/imports/Spectral/Component/ScrollHelper.qml +* +* The MouseArea + interactive: false + maximumFlickVelocity are required +* to fix scrolling for desktop systems where we don't want flicking behaviour. +* +* See also: +* ScrollView.qml in qtquickcontrols +* qquickwheelarea.cpp in qtquickcontrols +*/ +MouseArea { + id: root + propagateComposedEvents: true + + property Flickable flickable + property alias enabled: root.enabled + + //Place the mouse area under the flickable + z: -1 + onFlickableChanged: { + if (enabled) { + flickable.interactive = false + flickable.maximumFlickVelocity = 100000 + flickable.boundsBehavior = Flickable.StopAtBounds + root.parent = flickable + } + } + + function calculateNewPosition(flickableItem, wheel) { + //Nothing to scroll + if (flickableItem.contentHeight < flickableItem.height) { + return flickableItem.contentY; + } + //Ignore 0 events (happens at least with Christians trackpad) + if (wheel.pixelDelta.y == 0 && wheel.angleDelta.y == 0) { + return flickableItem.contentY; + } + //pixelDelta seems to be the same as angleDelta/8 + var pixelDelta = 0 + //The pixelDelta is a smaller number if both are provided, so pixelDelta can be 0 while angleDelta is still something. So we check the angleDelta + if (wheel.angleDelta.y) { + var wheelScrollLines = 3 //Default value of QApplication wheelScrollLines property + var pixelPerLine = 20 //Default value in Qt, originally comes from QTextEdit + var ticks = (wheel.angleDelta.y / 8) / 15.0 //Divide by 8 gives us pixels typically come in 15pixel steps. + pixelDelta = ticks * pixelPerLine * wheelScrollLines + } else { + pixelDelta = wheel.pixelDelta.y + } + + if (!pixelDelta) { + return flickableItem.contentY; + } + + var minYExtent = flickableItem.originY + flickableItem.topMargin; + var maxYExtent = (flickableItem.contentHeight + flickableItem.bottomMargin + flickableItem.originY) - flickableItem.height; + + if (typeof(flickableItem.headerItem) !== "undefined" && flickableItem.headerItem) { + minYExtent += flickableItem.headerItem.height + } + + //Avoid overscrolling + return Math.max(minYExtent, Math.min(maxYExtent, flickableItem.contentY - pixelDelta)); + } + + onWheel: { + var newPos = calculateNewPosition(flickable, wheel); + // console.warn("Delta: ", wheel.pixelDelta.y); + // console.warn("Old position: ", flickable.contentY); + // console.warn("New position: ", newPos); + + // Show the scrollbars + flickable.flick(0, 0); + flickable.contentY = newPos; + cancelFlickStateTimer.start() + } + + + Timer { + id: cancelFlickStateTimer + //How long the scrollbar will remain visible + interval: 500 + // Hide the scrollbars + onTriggered: flickable.cancelFlick(); + } +} diff --git a/resources/qml/TimelineView.qml b/resources/qml/TimelineView.qml index cad341b5..ce8ad62c 100644 --- a/resources/qml/TimelineView.qml +++ b/resources/qml/TimelineView.qml @@ -116,19 +116,10 @@ Page { boundsBehavior: Flickable.StopAtBounds pixelAligned: true - MouseArea { - anchors.fill: parent - acceptedButtons: Qt.NoButton - propagateComposedEvents: true - z: -1 - onWheel: { - if (wheel.angleDelta != 0) { - chat.contentY = chat.contentY - wheel.angleDelta.y - wheel.accepted = true - chat.returnToBounds() - } - } - } + ScrollHelper { + flickable: parent + anchors.fill: parent + } Shortcut { sequence: StandardKey.MoveToPreviousPage diff --git a/resources/res.qrc b/resources/res.qrc index c94f0f19..c6daaa80 100644 --- a/resources/res.qrc +++ b/resources/res.qrc @@ -118,6 +118,7 @@ qml/StatusIndicator.qml qml/EncryptionIndicator.qml qml/TimelineRow.qml + qml/ScrollHelper.qml qml/delegates/MessageDelegate.qml qml/delegates/TextMessage.qml qml/delegates/NoticeMessage.qml