Rectangle does not cover the entire ApplicationWindow

[ambershark]

@Eager I tested this code and it works fine on my Linux desktop. I didn't deploy to any android device, but it seems to work fine on the desktop version.

Does yours fail on desktop as well as the android device or just on the device?

[Eager]

@SGaist I have updated the question, now including the main.cpp file too.

I'm using Qt5.9.2, Android7.0, Samsung Note-5, Windows-10 for development .

I don't get the same issue on desktop.

I noticed that if I comment the following line in main.cpp then I don't get that issue but in that case the UI elements like labels, buttons etc looks very small (like zoomed out).

QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

I need few rectangles in the UI which cover the entire WIDTH of the screen but this issue has stopped my any further development, because I get about a pixel wide space left on the right side of the screen.

Even if I use Window instead of ApplicationWindow, I get the same results.

[Eager]

@ambershark It did not fail on desktop, It fails on my android device Samsung Note-5 Android Version 7.0

I have placed the main.cpp code in the question if you need for testing.

I have found that if I comment the following line of code in main.cpp then the issue goes away but then UI elements like buttons, labels, etc look very small like zoomed out.

QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

I really need a way to place few FULL WIDTH rectangles in ApplicationWindow without any artifacts but not at the cost of smaller UI elements.

[GrecKo]

It seems to be a bug due to the high dpi scaling, maybe a rounding issue or whatever.

If I was in your position I'd do anchors.margin: -1 as a workaround and check/report on https://bugreports.qt.io (ah, you already did).

[Eager]

@GrecKo I found this here: http://doc.qt.io/qt-5/qtquick-positioning-anchors.html

Note: Anchor margins only apply to anchors; they are not a generic means of applying margins to an Item. If an anchor margin is specified for an edge but the item is not anchored to any item on that edge, the margin is not applied.

As Items can't be anchored(but can be positioned using x and y) to ApplicationWindow itself so unfortunately your solution is not working.

I noticed that EVEN IF i make rectangle size bigger than window, I get the same issue!

I am still hunting a workaround :(

[GrecKo]

You can do anchors.fill: parent in a Window though. Here parent is the contentItem of the Window.
Or alternatively you could try width: window.width + 1

EDIT : didn't read the part about the bigger rectangle not working, too bad.

[Eager]

@GrecKo

• anchors.fill: parent
• width: window.width + 1

I tried them both separately and in combine but in both cases the result is same.

[Vinod Kuntoji]

@Eager ,

ApplicationWindow {
visible: true
Rectangle{
border.color: "red"
color;"black"
x:1
y:1
width: parent.width-1
height: parent.height-1
}

[Eager]

@Vinod-Kuntoji Note that I want to cover the entire red background with the BLACK rectangle.

This following code generates output shown in the next snapshot:

ApplicationWindow {
    id: window
    visible: true

    color: "#ff0000" // Red color window

    Rectangle{
        color: "#000000" // Black color Rectangle
        border.color: "#000000" // Black color Rectangle Border.
        x:0
        y:0
        width: parent.width+1
        height: parent.height+1
    }
}

OUTPUT:

The following code which is, in fact, your code generate output shown in the next snapshot:

ApplicationWindow {
    id: window
    visible: true

    // No color: means white background.    
    
    Rectangle{
        border.color: "red" // Red color Rectangle Border.
        color: "black" // Black color Rectangle
        x:0
        y:0
        width: parent.width-1
        height: parent.height-1
    }
}

OUTPUT:

[Eager]

@GrecKo I found that it is a bug that is affecting all platforms with certain screen resolutions. Some developers may not notice this issue but the end user may be using a certain screen resolution and be affected by the issue! You can login to https://bugreports.qt.io/ and Vote THIS bug if you also want this bug to be resolved.