controlling the size of a PlotItem and Gradient widget as a function of another PlotItem?

[Vincent Le Saux]

Dear all,

I'm currently implementing an ImageWidget on PyQtGraph, very similar to the ImageView widget, but with some layout modifications and the addition of a dedicated axisitem to the gradient (screenshot provided in attachement : file named ImageWidget.png). This widget is composed of 3 widgets connected together:

   - a PlotWidget displaying an image (widget 1)

   - a GradientWidget composed of a colorbar and an axis indicating the values related to the colobar (widget 2)

   - a PlotWidget displaying the histogram of the image and a LinearRegionItem connected to the colorbar and its axis (widget 3)

Everything is fully functionnal, but there remains two problems:

 1. I want the size of the colorbar (and its axis) to be exactly the same as the widget 1 PlotItem (and in the prolongation) as illustrated by the red element in the fileImageWidget_wanted.png. I would like to It is possible to do that in PyQtGraph?

 2. I would like to adapt the size of the PlotItem axis of widget 3 so that its width is exactly the same as the widget 1 PlotItem axis (in the prolongation in fact) as illustrated by the blue lines in the file ImageWidget_wanted.png. Is it possible with PyQtGraph?

Any help will be grealty appreciated. When these problems are solved, I will of course provide the source code!

Regards,

vls 

[Luke Campagnola]

Looks really good!

On Thu, Jul 3, 2014 at 5:44 PM, Vincent Le Saux <vincent...@gmail.com> wrote:

Everything is fully functionnal, but there remains two problems:

 1. I want the size of the colorbar (and its axis) to be exactly the same as the widget 1 PlotItem (and in the prolongation) as illustrated by the red element in the fileImageWidget_wanted.png. I would like to It is possible to do that in PyQtGraph?

Perhaps use QGraphicsWidget.setMaximumHeight() and setMinimumHeight() to enforce the size, or add a spacer of fixed size to the layout. Either way, you'll need to have some code that reacts when the widget is resized.

 

 2. I would like to adapt the size of the PlotItem axis of widget 3 so that its width is exactly the same as the widget 1 PlotItem axis (in the prolongation in fact) as illustrated by the blue lines in the file ImageWidget_wanted.png. Is it possible with PyQtGraph?

Same solution as above. You might also find that it is easier to do without the layout entirely and manually set the position / size of each widget whenever the top level widget is resized.

[Luke Campagnola]

On Thu, Jul 3, 2014 at 5:44 PM, Vincent Le Saux <vincent...@gmail.com> wrote:

Everything is fully functionnal, but there remains two problems:

 1. I want the size of the colorbar (and its axis) to be exactly the same as the widget 1 PlotItem (and in the prolongation) as illustrated by the red element in the fileImageWidget_wanted.png. I would like to It is possible to do that in PyQtGraph?

 2. I would like to adapt the size of the PlotItem axis of widget 3 so that its width is exactly the same as the widget 1 PlotItem axis (in the prolongation in fact) as illustrated by the blue lines in the file ImageWidget_wanted.png. Is it possible with PyQtGraph?

There's another solution here that might make more sense: Try adding all of the sub-components of each plot to a single grid. This would ensure that the boundaries all line up automatically. You could, for example, take the AxisItems, ViewBox, and LabelItems from widget 3 and add them into the layout used by widget 1.

[Vincent Le Saux]

This is exactly what I did (using a QGridLayout). However, I had to add a "blank" label over the left axis to make sure the plotItem size of the two widgets are exactly the same. 

I'll test your solution regarding the colorbar size. 

I should be able to provide the source code this week (if someone is interested in of course).

Thanks for your time!

Regards, 

Vincent

[Nicholas Tan Jerome]

I am interested :)

[mgele...@gmail.com]

Hi Vincent,

I'd be really interested to see your code for this if you've still got it!

Cheers,

Michael