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qtdeclarative/examples/quick/pointerhandlers/pieMenu.qml

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Use SPDX license identifiers Replace the current license disclaimer in files by a SPDX-License-Identifier. Files that have to be modified by hand are modified. License files are organized under LICENSES directory. Pick-to: 6.4 Task-number: QTBUG-67283 Change-Id: I63563bbeb6f60f89d2c99660400dca7fab78a294 Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
2022-05-13 13:12:05 +00:00
// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
Add TapHandler.gesturePolicy: DragWithinBounds enum value; examples On a touchscreen, right-clicking is not directly possible; so sometimes a long-press gesture is used as a substitute. The next thing a UI designer would want would then be a way of showing feedback that a long-press is in progress, rather than simply waiting for the long-press to occur and then surprising the user with some instant action. For example, a menu might begin to open as the user holds down the touchpoint; but before the long-press gesture is complete, the user can simply release, to cancel the gesture and close the menu. The timeHeld property could drive the animation, to avoid needing a separate animation type; in fact the reason timeHeld exists is to make it easy to emulate this sort of touch-press animation, like one that occurs on touchscreens since Windows 7. But after the menu is open, the user would probably expect to be able to drag the finger to a menu item and release, to select the menu item. For such a purpose, the existing gesture policies weren't very useful: each of them resets the timeHeld property if the user drags beyond the drag threshold; so if the user expects to drag and release over a menu item, then the timeHeld property cannot drive the menu-opening animation, because the menu would disappear as soon as the user drags a little. So it makes more sense to have a gesturePolicy that acts like WithinBounds, but also applies the same policy to the timeHeld property and the longPressed signal. We don't care about the drag threshold: if the user is holding down a finger, it's considered to be a long-press-in-progress, regardless of how far it has moved since press (as long as it stays within the parent's bounds). An example of such a menu is added. The menu must have TapHandler as its root object, because it reacts to press-and-drag within some larger item, larger than the menu itself. For example such a menu could be used in a canvas-like application (drawing, diagramming, dragging things like photos or file icons, or something like that): dragging items on the canvas is possible, but long-pressing anywhere will open a context menu. But in this example so far, only the menu is implemented. It's a pie menu, because those are particularly touch-friendly; but perhaps for the mouse, a conventional context menu would be used. [ChangeLog][QtQuick][Event Handlers] TapHandler now has one more gesturePolicy value: DragWithinBounds; it is similar to WithinBounds, except that timeHeld is not reset during dragging, and the longPressed signal can be emitted regardless of the drag threshold. This is useful for implementing press-drag-release components such as menus, while using timeHeld to directly drive an "opening" animation. Change-Id: I298f8b1ad8f8d7d3c241ef4fdd68e7ec8d8b5bdd Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>
2021-10-07 20:27:32 +00:00
import QtQuick
import "components"
Item {
width: 800
height: 480
Rectangle {
id: rect
anchors.fill: parent; anchors.margins: 40
color: pieMenu.active ? "lightgrey" : "darkgrey"
QuadPieMenu {
id: pieMenu
labels: [ "whiz", "bang", "fizz", "buzz" ]
onTriggered: (text)=> feedback.text = "selected **" + text + "**"
onCanceled: feedback.text = "canceled"
}
Text {
id: feedback
x: 6; y: 6
textFormat: Text.MarkdownText
text: "hold for context menu"
}
}
}