Copy of QPalette modifies original

[hispeedsurfer]

Question of comprehension

I would like to temporarily change the text color in the StatusBar.

Question is, why does the original palette change after the modified palette has been assigned to the StatusBar?

I already know how to solve this by simply resetting the color.

const QPalette& palOrg = statusBar()->palette();
 
QPalette palCopy = palOrg;
 
palCopy.setColor(QPalette::WindowText, Qt::red);
 
qDebug() << palCopy.color(QPalette::WindowText) << palOrg.color(QPalette::WindowText);
//logs QColor(ARGB 1, 1, 0, 0) QColor(ARGB 1, 0, 0, 0)
 
statusBar()->setPalette(palCopy);
 
qDebug() << palCopy.color(QPalette::WindowText) << palOrg.color(QPalette::WindowText);
//logs QColor(ARGB 1, 1, 0, 0) QColor(ARGB 1, 1, 0, 0)

const QPalette& palOrg = statusBar()->palette();

QPalette palCopy = palOrg;

palCopy.setColor(QPalette::WindowText, Qt::red);

qDebug() << palCopy.color(QPalette::WindowText) << palOrg.color(QPalette::WindowText);
//logs QColor(ARGB 1, 1, 0, 0) QColor(ARGB 1, 0, 0, 0)

statusBar()->setPalette(palCopy);

qDebug() << palCopy.color(QPalette::WindowText) << palOrg.color(QPalette::WindowText);
//logs QColor(ARGB 1, 1, 0, 0) QColor(ARGB 1, 1, 0, 0)

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[Ginsengelf]

Hi, I think it's because statusBar()->palette() returns a QPalette&. So "palOrg" references the internal QPalette object of the status bar, and since it's a reference it reflects all changes made to the object it "points" to.

Ginsengelf