How to make animated backgrounds?

Pl45m4

LOL that looks hilarious :D
Didn't know that it was possible. Also thanks to @Bonnie

Bonnie

@Mizmas said in How to make animated backgrounds?:

Would this be most straightforward method if you want to lay everything out in QT Designer?

I have another approach, but I don't know how to do that in PyQt, so I'll just show it in C++.
To make a widget in designer still acting like a QWidget/QFrame, but actually being a QLabel, we can use promoting.
(In case anyone don't know about promoting widgets, here's the documentation: https://doc.qt.io/qt-6/designer-using-custom-widgets.html#promoting-widgets)
So right click the background widget and select "Promote to ...".
It would be great if we can promote it to QLabel directly, sadly designer doesn't allow that, so we promote it to a custom class name, say "QLabelWidget" with the header file "qlabelwidget.h".
Then create "qlabelwidget.h" with below content:

#ifndef QLABELWIDGET_H
#define QLABELWIDGET_H
#include <QLabel>
typedef QLabel QLabelWidget;
#endif // QLABELWIDGET_H

So the background widget will become a QLabelWidget, aka QLabel. You cannot edit its QLabel properties in the designer, but it can call QLabel member functions in the code. Since QMovie can only be set in the code, I think that's not a problem.

Mizmas

@Bonnie Yes, that's definitely more straight forward, thanks again :D

Mizmas

I've been experimenting some more with gif backgrounds, subclassing a QFrame using QLabel.
I tried making a background for a push button, and the background gif changes based whether the cursor is hovering over the button or not.
This is what I have so far: https://streamable.com/k02xqk

# set initial state for website button
    self.website_button_frame = self.findChild(GifFrame, 'website_button_frame')
    self.gif = QMovie(':/animations/website_logo.gif')
    self.gif.setScaledSize(self.website_button_frame.size())
    self.website_button_frame.setMovie(self.gif)
    self.gif.start()
    
    # Install an event filter on the website button
    self.website_button.installEventFilter(self)

# website_button hover/not hover filter
def eventFilter(self, watched, event):
    if watched == self.website_button:
        if event.type() == QEvent.Type.Enter:
            # Action when hovering
            gif = QMovie(":/animations/website_logo_purple.gif")
            gif.setScaledSize(self.website_button_frame.size())
            self.website_button_frame.setMovie(gif)
            gif.start()
        elif event.type() == QEvent.Type.Leave:
            # Action when not hovering
            gif = QMovie(":/animations/website_logo.gif")
            gif.setScaledSize(self.website_button_frame.size())
            self.website_button_frame.setMovie(gif)
            gif.start()
    return super().eventFilter(watched, event)

Basically, I'm using two gifs with two different colors, they both have transparent backgrounds and solid color objects. I'm using an event filter to change the two, based on whether the cursor is hovering over the button or not. The problem is that this transition is not smooth and jittery. This is because both the QMovie objects start over again from the start and not on the frame that was displayed before. I've tried using methods of the QMovie like currentFrameNumber() and jumpToFrame(), but they only seem to work if you're using the same QMovie (at least I couldn't get it to work).

Is there some approach I can take to work with a single .gif file, and somehow programmatically change the color of the solid color objects while the gif is playing? Or is there some different stuff I can try, maybe outside of QT?

GrecKo

There is some different stuff you can try, inside Qt. Namely Qt Quick.
In my opinion it is much more suited to the kind of application you appear to make.
QtQuick.Effects's MultiEffect can color any abritrary item

For fun I tried to recreate the stuff you showed in QML with Qt Quick, here's the quick and a bit ugly code:

import QtQuick
import QtQuick.Controls
import QtQuick.Effects

ApplicationWindow {
    id: window
    width: 640
    height: 480
    visible: true

    property real radius: 8

    flags: Qt.FramelessWindowHint
    color: "transparent"

    Rectangle {
        parent: window.contentItem.parent
        z: -1
        anchors.fill: parent
        color: "#F7BF8A"
        radius: window.radius
        border.width: 1
    }
    footer: Rectangle {
        color: "#B1C368"
        height: 50
        topLeftRadius: 0
        topRightRadius: 0
        bottomLeftRadius: window.radius
        bottomRightRadius: window.radius
        border.width: 1
        Text {
            id: siteLink
            anchors {
                verticalCenter: parent.verticalCenter
                right: parent.right
                rightMargin: 20
            }
            text: "By midimagic"
            font.family: "Courier New"
            color: hoverHandler.hovered ? "#8D7BDE" : "black"

            HoverHandler {
                id: hoverHandler
                cursorShape: Qt.PointingHandCursor
            }
            TapHandler {
                onTapped: Qt.openUrlExternally("https://forum.qt.io")
            }
            AnimatedImage {
                id: siteGif
                visible: false
                anchors {
                    fill: parent
                    margins: -15
                }
                source: "https://emoji.discadia.com/emojis/d3897e57-3a33-4136-a6bb-882343233261.gif"
                fillMode: Image.PreserveAspectFit
            }
            MultiEffect {
                anchors.fill: siteGif
                source: siteGif
                colorizationColor: siteLink.color
                colorization: 1
            }
        }
    }
}

Here's the result: ( the sluggyness is only in the recording, it runs smooth)
colored background gif

Mizmas

@GrecKo Damn :D I've never used QT Quick before, but thank you so much

GrecKo

Alternatively if you want to stick with QWidgets you could retrieve the current frame number of the running QMovie and set it to the new one when switching. With currentFrameNumber and jumpToFrame.

Mizmas

@GrecKo Yeah I've tried again using currentFrameNumber() and jumpToFrame() and it seems to work, I must've messed something up before. Thanks again

Mizmas

@GrecKo Though, there are times where the gifs begin to lag and slow down for a moment, even when the cursor is not interacting with them. This happens on all other QMovie objects with gifs that I've tried, even if there's no cursor interaction coded

artwaw

@Mizmas please check the release version of your program, the debug ones can be laggy for obvious reasons.