PointerScrollEvent QML Type

Provides information about a scrolling event, such as from a mouse wheel. 更多...

import 語句：

import QtQuick 2.15

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特性

angleDelta : point
buttons : int
device : PointerDevice
hasAngleDelta : bool
hasPixelDelta : bool
inverted : bool
modifiers : int
pixelDelta : point

詳細描述

另請參閱 WheelHandler .

特性文檔編製

angleDelta : point

This property holds the distance that the wheel is rotated in wheel degrees. The x and y cordinate of this property holds the delta in horizontal and vertical orientation.

A positive value indicates that the wheel was rotated up/right; a negative value indicates that the wheel was rotated down/left.

大多數鼠標類型以 15 度步幅為單位工作，在這種情況下，增量值是 120 的倍增 (即：120 單位 *1/8 = 15 度)。

buttons : int

This property holds the mouse buttons pressed when the wheel event was generated.

It contains a bitwise combination of:

[read-only] device : PointerDevice

This property holds the device that generated the event.

hasAngleDelta : bool

Returns whether the angleDelta property has a non-null value.

hasPixelDelta : bool

Returns whether the pixelDelta property has a non-null value.

inverted : bool

返迴隨事件交付的增量值是否反轉。

通常，垂直滾輪會産生 PointerScrollEvent 具有正增量值若滾輪頂部鏇轉離開操作它的手。同樣，水平滾輪運動會産生 PointerScrollEvent 具有正增量值若滾輪頂部嚮左移動。

However, on some platforms this is configurable, so that the same operations described above will produce negative delta values (but with the same magnitude). In a QML component (such as a tumbler or a slider) where it is appropriate to synchronize the movement or rotation of an item with the direction of the wheel, regardless of the system settings, the wheel event handler can use the inverted property to decide whether to negate the angleDelta or pixelDelta 值。

注意： Many platforms provide no such information. On such platforms, inverted always returns false.

[read-only] modifiers : int

此特性保持 keyboard modifier keys that were pressed immediately before the event occurred.

It contains a bitwise combination of the following flags:

常量	描述
`Qt.NoModifier`	未按下修飾符鍵。
`Qt.ShiftModifier`	按下鍵盤 Shift 鍵。
`Qt.ControlModifier`	按下鍵盤 Ctrl 鍵。
`Qt.AltModifier`	按下鍵盤 Alt 鍵。
`Qt.MetaModifier`	按下鍵盤 Meta 鍵。
`Qt.KeypadModifier`	按下 Keypad (小鍵盤) 按鈕。

For example, to react to a Shift key + Left mouse button click:

Item {
    TapHandler {
        onTapped: {
            if ((event.button == Qt.LeftButton) && (event.modifiers & Qt.ShiftModifier))
                doSomething();
        }
    }
}

pixelDelta : point

This property holds the delta in screen pixels and is available in platforms that have high-resolution trackpads, such as macOS. The x and y coordinates of this property hold the delta in horizontal and vertical orientation. The value should be used directly to scroll content on screen.

For platforms without high-resolution touchpad support, pixelDelta will always be (0,0), and angleDelta 應該被使用以取而代之。