Qt Quick Toolbar: Gradient editor usability is difficult

If you use the Qt Quick Toolbar for editing a Rectangle that has a gradient, it is really difficult to move the gradient stops in the UI to the correct location.

The problem is that the user cannot easily drag the gradient stop to 0.0 and 1.0, because if you drag the cursor outside the toolbar, the drag stops entirely. Because 0.0 and 1.0 are very common values to use when editing a gradient, this makes the gradient editor really difficult to use and leads the user to simply type in the values.

Additionally, there are no tooltips for showing the gradient stop positions while dragging, so the user has to look in two places at the same time: the text editor, showing the Gradient {} block, and the gradient editor toolbar.