QML and Qt Quick

Are you on a very resource constrained system? Without having looked much at the code, I would guess that it spends the extra CPU simply because the entire rectangle is filled even if you only modify the border color. When borders are translucent, rounded or antialiased it often requires repainting the whole thing, so it generally just calls update() on the whole Item rect. It might be possible to special case this, but for now I think your fix sounds reasonable as it sounds like your bottle neck is simply the amount of pixels you can push and it might require managing each rect at a lower level.

You should be able to modify the signal handler from JS like this: @ State { name: "one" StateChangeScript { script: { area.clicked.disconnect( handleOne ); area.clicked.connect( handleTwo ); } } @ But note: if you add a handler to clicked while this event is currently handled, the newly added handler will be called immediatly.

I am also curious if there is a way to "borrow" the geometry QPainter generates when used on a OpenGL paint device, that could prove useful and save math headaches.

And now I will answer first problem myself: blog I'm pointing to has mistype "n" is missing in isAtYBeginning. ListView still inherits from Flickable (can be seen while reading code). Second problem is more complicated however.

Did you register the class, i.e. the second step of my example?

Just use a placeholder to center your rotating item into. Here is an example - the rotating item will move with the mouse cursor as it rotates around its center and changes width: @Rectangle { id: root width: 800 height: 800 color: "yellow" MouseArea { id: cursorLocation hoverEnabled: true anchors.fill: parent } Item { // placeholder width: 50 height: 50 x: cursorLocation.mouseX - width/2 y: cursorLocation.mouseY - height/2 Rectangle { id: tester anchors.centerIn: parent width: 50 height: 50 color: "black" NumberAnimation on rotation { loops: Animation.Infinite from: 0 to: 360 duration: 1000 } NumberAnimation on width { loops: Animation.Infinite from: 50 to: 300 duration: 1000 } } } }@

Thanks for you answer!

Hello, thanks for the answers. chrisadams , I didn't know about beginCreateObject, I'll try it! Maybe I could use the C++ side of the animation engine, or maybe use a QtObject for each line just to handle state and position, and do the drawing in a shared item... Jens, this was "option three": using an QSGItem directly. Unfortunately this approach works, but requires to generate a low level tessellation of the geometry. This means that you cannot use all the QPainter goods, and you need to generate the vertexs, color coordinates, textures (line caps, joins,effects,gradients, etc...). This will be much faster but requires a good amout of work. And even in this case I "suspect" that I'll have to share vertex buffers, I don't think creating a number of small nodes/buffers will be so good in terms of performance...

I'm using 4.8.4. I don't think it can be done. There doesn't seem to be a way I can trap that event when I create the keyboard dynamically.

Perhaps you can upload your files somewhere so other people can try it on their local machine.

Ah, you are using Qt4... it seems there is no such property in QtQuick 1...

Exactly. While there is no reason why that shouldn't be possible using pure QML. P.S. Maybe that's possible using webkit but that's different topic.

It is the anchors which define how the child rectangle fills the parent rectangle. Remember, in QML, just because an object instance is declared within another one does NOT mean that it is visually located inside that other one. The positioning (either via anchors, or some other positioning method) define where it "appears" and thus the positioning also defines the spacing / padding. So, to implement what you want, just add an "anchors.margins: 10" to your anchors declaration. Note that the margin can also be specified separately for each edge; see http://doc-snapshot.qt-project.org/qt5-stable/qtquick/qtquick-positioning-anchors.html for more information. Cheers, Chris.

Thank you. That was what I was doing but there was a typo blush

Just cloned it. Thanks a lot

Done! Thanks:)