问题
I have a tab bar with a stacklayout like the following:
Rectangle {
id: rect
height: 190
anchors.right: parent.right
anchors.left: parent.left
color: "transparent"
anchors.top: uniqueHandleText.bottom
anchors.topMargin: 100
TabBar {
id: frame
anchors.right: parent.right
anchors.left: parent.left
background: Rectangle {
color: "#737373"
}
x: -hbar.position * width
Repeater {
model: wizard.categories
TabButton {
id: tabData
property bool selected: false
text: modelData.name
width: 200
font.pixelSize: 18
contentItem: Text {
text: tabData.text
font: tabData.font
horizontalAlignment: Text.AlignHCenter
verticalAlignment: Text.AlignVCenter
elide: Text.ElideRight
wrapMode: Text.WordWrap
color: "#FFFFFF"
}
background: Rectangle {
implicitWidth: frame.width
implicitHeight: 180
opacity: enabled ? 1 : 0.3
color: tabData.checked ? "#BD9CBE": "#737373"
}
}
}
}
ScrollBar {
id: hbar
hoverEnabled: true
active: hovered || pressed
orientation: Qt.Horizontal
size: rect.width / frame.width
anchors.left: parent.left
anchors.right: parent.right
anchors.top: frame.bottom
}
Text {
font.pixelSize: 18
text: "Next"
anchors.right: parent.right
visible: frame.x != frame.width ? true: false
}
StackLayout {
id: stack1
anchors.left: parent.left
anchors.right: parent.right
anchors.top: frame.bottom
currentIndex: frame.currentIndex
Repeater {
model: wizard.categories
Item {
id: homeTab
TabBar {
id: homeTabTab
anchors.right: parent.right
anchors.left: parent.left
anchors.top: parent.top
height: 180
background: Rectangle {
color: "#958096"
}
Repeater {
model: modelData.sub_categories
TabButton {
property bool selected: false
id: currentTab
text: modelData.name
width: 200
font.pixelSize: 18
background: Rectangle {
implicitWidth: frame.width
implicitHeight: 180
opacity: enabled ? 1 : 0.3
color: currentTab.checked ? "#958096": "#8D758E"
}
contentItem: Text {
text: currentTab.text
font: currentTab.font
horizontalAlignment: Text.AlignHCenter
verticalAlignment: Text.AlignVCenter
elide: Text.ElideRight
wrapMode: Text.WordWrap
color: "#FFFFFF"
MouseArea {
anchors.fill: parent
onClicked: {
if(currentTab.checked){
currentTab.checked = false
} else {
currentTab.checked = true
}
}
onDoubleClicked: {
currentTab.selected = true
var found = false;
var someText = frame.itemAt(stack1.currentIndex).text;
print(someText)
for(var i = 0; i<wizard.selectedSkills.count; i++){
if(wizard.selectedSkills.get(i).name === someText){
wizard.selectedSkills.get(i).sub_categories.append({"name":currentTab.text});
wizard.skills.push({"name": someText})
found = true;
}
}
if(!found){
print(currentTab.text)
wizard.selectedSkills.append({"name":someText, "sub_categories":[{"name":currentTab.text}]})
}
print(window.selectedSkills)
}
}
}
}
}
}
}
}
}
}
I've tried many different things to add a scrollbar or to figure out how to use the flickable functionality that TabBar has. However, the documentation doesn't specify how it works, it just does. Therefore, they are not accessible (or even rewritteable, to use those properties). I want to add a small indicator like an arrow to specify that there is more elements for ease of navigation on desktop on top of the TabBar functionality.
回答1:
It doesn't seem like the necessary properties are exposed in order to make this happen the easy way.
However, since this is QML, it means the whole object tree is gaping wide open to introspection, allowing us to establish that the item that does the flicking is the contentItem of a ListView inside the Container the ToolBar inherits. The view happens to be the second visible child, although this is technically "private implementation" that one should not rely on. So it is better to take some extra care to establish whether or not you have the correct object.
ApplicationWindow {
id: main
width: 640
height: 480
visible: true
TabBar {
id: toolbar
width: parent.width
height: 50
Repeater {
model: 10
TabButton {
text: "test " + index
width: 100
}
}
}
Rectangle {
height: 5
width: main.width * (view ? view.visibleArea.widthRatio : toolbar.width / toolbar.contentWidth)
color: "red"
anchors.top: toolbar.bottom
x: view ? (main.width - width) * (view.contentX / (view.contentWidth - view.width)) : 0
}
property ListView view: {
var l = toolbar.visibleChildren.length
while (--l) if ("cacheBuffer" in toolbar.visibleChildren[l]) return toolbar.visibleChildren[l]
return null
}
}
And there you have it. We iterate the tabview children until we find one that has a property cacheBuffer which is fairly unique to ListView, and once we have that, we can access the needed properties. As you see, for the indicator width we can do even without the list view, as the toolbar exposes a contentWidth property, but for the indicator position there is no workaround.
And it works:
来源：https://stackoverflow.com/questions/48736260/long-tabbar-adding-a-size-and-position-indicator-to-reflect-the-presence-of-of