I have this statement inside my QML item:
Rectangle {
// ...
anchors.right: someItemID.right
// ...
}
I'm receiving this warning for my Rectangle item:
QML Rectangle: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
How can I use Layout.alignment to resolve the above warning? How can I pass another item ID to Layout.alignment? Is it possibe?
A layout manages the positions and sizes of all of its child items. Using anchors inside child items is not allowed as it could override these rules. You can only influence those properties provided by the layout in the Layout object attached to its children, which is hinted at in the warning message. Layout.alignment controls how the item is aligned within the cell created for it by the layout. You can therefore align an item to the edges of its adjacent cells, but you can't directly anchor to their items by ID.
If you need more precise control, you should position the items outside the layout using position and/or anchor properties.
Related
I have the following code:
ListView {
delegate: MyDelegate {
MouseArea {
anchors.fill: parent
/*some other stuff*/
}
}
}
The problem is that MyDelegate contains checkboxes and MouseArea "steals" mouse events from them. They do not react on mouse events at all, i.e. do not work as expected.
I know about propagateComposedEvents property of MouseArea...but I'll have to implement all of its mouse events (clicked, pressed, released,...) and check whether the mouse cursor is in the checkbox or not to set mouse.accepted property accordingly.
This is how I understood all of these currently. Is there any easier way, i.e. a way to be able to process all of the mouse events for areas that does not handle mouse events explicitly? For instance static text, progress bars, etc.
You can apply negative values to the z property of the MouseArea.
From the documentation:
Items with a higher stacking value are drawn on top of siblings with a lower stacking order. Items with the same stacking value are drawn bottom up in the order they appear. Items with a negative stacking value are drawn under their parent's content.
I have two shapes in my canvas using CreateJS. In each shape I included a hit area with the own shape with a mouseover listener. Two shapes are one above the other. When I click into the shape, I received the two callbacks. It's possible to get only the callback to the visible shapes?
enter image description here
Similar to the DOM, the way mouse interaction works is to bubble up the display list, which excludes elements that are not part of the hierarchy chain of the event target.
This means siblings, or elements of other display lists that are underneath will not receive event handlers (which is what you described), and you will not receive mouse events for elements that are not the target of the mouse event.
However, you can wire up your own interaction fairly easily using getObjectsUnderPoint, which tells you what is under the mouse.
stage.on("click", handleClick);
function handleClick(event) {
var list = stage.getObjectsUnderPoint(event.localX, event.localY);
for (var i=0, l=list.length; i<l; i++) {
console.log(list[i]);
}
}
Here is a quick sample: http://jsfiddle.net/y8jhb26x/
Note that you can add the mouse event to any container you want to constrain what objects will trigger this check (I just used stage), but when you call getObjectsUnderPoint, it will return anything under the mouse. If you want to only check items in that container, you can use the contains method to filter out unwanted children:
for (var i=0, l=list.length; i<l; i++) {
if (someContainer.contains(list[i])) {
console.log(list[i]);
}
}
You can also use arguments on getObjectsUnderPoint to filter out items with mouse handlers, or respect the mouseChildren/mouseEnabled property, which is how actual mouse interaction works.
getObjectsUnderPoint method
mouse interaction code
Hope that helps!
I can show current selection QML ListView but similar thing doesn't work in TreeView.
Part of the problem is for TreeView it doesn't recognize index which is passed to delegate in case of ListView. I tried styleData.indexbut that doesn't work either.
rowDelegate: Item {
id: row_delegate
height: 40
Rectangle {
id: rectid
anchors.fill: parent
MouseArea {
id: mouse_area
anchors.fill: parent
onClicked: {
console.log("Row clicked " + rectid.styleData.index)
}
}
}
}
The output is:
qml: Row clicked undefined
As stated by the documentation, you have a set of properties within the namespace styleData that can be used for almost the same purposes from within a delegate.
As an example, you can set the text property of a label that is part of your delegate as it follows:
text: styleData.value
Where styleData.value is (documentation excerpt):
the value or text for this item
Similarly, you have:
styleData.pressed - true when the item is pressed
styleData.index - the QModelIndex of the current item in the model
styleData.hasChildren - true if the model index of the current item has or can have children
And so on... Please, refer to the documentation for the full list.
Be aware also of the note at the end of the documentation:
Note: For performance reasons, created delegates can be recycled across multiple table rows. This implies that when you make use of implicit properties such as styleData.row or model, these values can change after the delegate has been constructed. This means that you should not assume that content is fixed whenComponent.onCompleted is called, but instead rely on bindings to such properties.
I want to access delegate properties in ListView. I've tried with contentItem but sometimes it's undefined.
Here is my code:
ListModel{
id: modeldata
ListElement{
name:"don"
rank:1
}
ListElement{
name:"shan"
rank:2
}
ListElement{
name:"james"
rank:3
}
ListElement{
name:"jeggu"
rank:4
}
}
Component{
id: delegateitem
Row {
property int count: rank
Rectangle{
width: 100
height: 50
Text{
anchors.centerIn: parent
text: name
}
}
}
}
ListView{
id: listview
focus: true
anchors.fill: parent
model: modeldata
delegate: delegateitem
onCurrentIndexChanged: {
console.log("position",currentIndex)
console.log("property",contentItem.children[currentIndex].count);
}
}
Problem invalid output at position 1
qml: position 0
qml: property 1
qml: position 1
qml: property undefined
qml: position 2
qml: property 2
qml: position 3
qml: property 3
#Teimpz didn't really explain it well. Especially since there are bunch of qt project and ubuntu touch qml examples and use cases where you manage dynamically created list elements using javascript, and that is why they have javascript methods and properties
In QML there is more a notion of parent than a child, which is common in html. In bigger projects it is recommended (as you can also see in qt examples and in docs http://doc.qt.io/qt-5/qtqml-javascript-expressions.html#functions-in-imported-javascript-files) to have js logic separate from qml elements so you do access and manage elements from outside rather than pollute you qml elements with js logic, but not in a way of looking for children elements, but rather exposing children elements that you need.
In your case you should just use currentItem, same as you use currentIndex, so currentItem.count will give you what you need.
And if you don't need current item at all, you can access elements from model directly:
modelData.get(currentIndex).count, or listview.model.get(currentIndex).count
As for the hack that is mentioned by #Teimpz that is also one bad example. When you have more complex requirements and wanting specific elements inside delegate, every delegate has ListView.isCurrentItem property which you can attach and check. This would mean you can add property var myTargetItem to listview, and set it from child to whatever element you want if that delegate is current http://doc.qt.io/qt-5/qml-qtquick-listview.html#isCurrentItem-attached-prop
You can of course do that for any kind of event, maybe activeFocus so you could only reference activeFocused item.
This once again give you ability to expose only wanted elements without any advanced logic or lopping. Combining this with signals you can create very complex but clean interfaces without searching through children items.
So in the end maybe less nice but still better than searching for elements would be to add property int currentItemCount: 0 to listview. In delegate (Row element) you then add property bool isCurrentItem: ListView.isCurrentItem
so you get onIsCurrentItemChanged signal inside delegate, where you can do:
onIsCurrentItemChanged: if(isCurrentItem) listview.currentItemCount = count
so you have your current item count always set
The simple way is using itemAtIndex() like intemAt() in Repeater.
First of all: if you are trying to access list elements from outside your list, this is a good indicator that you should rethink your desing.
Now the solution: a listview has more children than only its items. You can filter them out by defining a property "property string type: "myType" " for example. Then find the items by looping over the children and only take those where the type property equals "myType".
Its somewhat of a hack but again you should really not be doing this in the first place.
myListView.itemAtIndex(currentIndex)).function_name()
I'm using a panel with border layout in which west region contains the tree and center region contains the panel which is extending from a panel with column layout. The tree is loading data from json (draggable). Items is adding to the panel at the center region when the user drops the node form tree. But for adding the itms in panel i'm using panel.add method which is always adding at the last position. But i want to add it wherever the user dropped it.
Tried with panel.add(droppeditem).showAt(e.getXY())
But it's giving the error as
Uncaught TypeError: Cannot call method 'translatePoints' of undefined.
Can anybody help me to achieve this
Regards
URL
I had the same error with a context menu on a tree panel. When I added the context menu view to the refs inside my controller with an xtype and an autoCreate set to true it fixed the problem. It is almost like the object (context menu) was not getting instantiated.
Example:
var contextMenu = this.getPortletMenuContext();
contextMenu.showAt(event.getXY());
I was getting the same error above until I added:
{ ref: 'portletMenuContext', selector: 'portletmenucontext', xtype: 'portletmenucontext', autoCreate: true }
To my refs inside my controller.