# how to fix the font size/length for vtkLegendScaleActor

**URL:** https://discourse.vtk.org/t/how-to-fix-the-font-size-length-for-vtklegendscaleactor/11874
**Category:** Support
**Created:** [July 4, 2023, 3:12pm UTC](https://discourse.vtk.org/t/how-to-fix-the-font-size-length-for-vtklegendscaleactor/11874 "2023-07-04T15:12:28Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![zhang-qiang-github](https://discourse.vtk.org/user_avatar/discourse.vtk.org/zhang-qiang-github/32/2519_2.png) [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)
#### Post date: [July 4, 2023, 3:12pm UTC](https://discourse.vtk.org/t/how-to-fix-the-font-size-length-for-vtklegendscaleactor/11874/1 "2023-07-04T15:12:28Z")

</div>

I use `vtkLegendScaleActor` in my project. When the window is resized, I expect the font size/length of `vtkLegendScaleActor` is fixed.

In the `resizeEvent`:

```auto
    def resizeEvent(self, evt) -> None:
        super().resizeEvent(evt)

        y = self.height()
        dy = round((y-100)/2)
        self.legendScaleActor.SetTopBorderOffset(dy)
        self.legendScaleActor.SetBottomBorderOffset(dy)
        self.legendScaleActor.GetLeftAxis().SetSizeFontRelativeToAxis(False)
        self.legendScaleActor.GetLeftAxis().UseFontSizeFromPropertyOn()
        self.legendScaleActor.GetLeftAxis().GetLabelTextProperty().SetFontSize(10)
        self.legendScaleActor.Modified()
        self.renderWindow.Render()

```

I find the setting in `resizeEvent` do not work. When I change the window size by mouse, I find the length of axis is changed, and the font size is also changed.

The complete code is:

```auto
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QVBoxLayout, QWidget
import vtk
from vtk.qt.QVTKRenderWindowInteractor import QVTKRenderWindowInteractor

class MainWindow(QMainWindow):
    def __init__ (self):
        super(MainWindow, self). __init__ ()

        self.vtkWidget = QVTKRenderWindowInteractor(self)
        self.renderer = vtk.vtkRenderer()
        self.renderWindow = self.vtkWidget.GetRenderWindow()
        self.renderWindow.AddRenderer(self.renderer)

        sphereSource = vtk.vtkSphereSource()
        sphereSource.SetCenter(0, 0, 0)
        sphereSource.SetRadius(1.0)

        sphereMapper = vtk.vtkPolyDataMapper()
        sphereMapper.SetInputConnection(sphereSource.GetOutputPort())
        sphereActor = vtk.vtkActor()
        sphereActor.SetMapper(sphereMapper)

        self.renderer.AddActor(sphereActor)

        self.legendScaleActor = vtk.vtkLegendScaleActor()
        self.renderer.AddActor(self.legendScaleActor)
        self.legendScaleActor.AllAxesOff()
        self.legendScaleActor.SetLeftAxisVisibility(True)

        layout = QVBoxLayout()
        layout.addWidget(self.vtkWidget)
        widget = QWidget()
        widget.setLayout(layout)
        self.setCentralWidget(widget)

        self.vtkWidget.Initialize()
        self.vtkWidget.Start()

    def resizeEvent(self, evt) -> None:
        super().resizeEvent(evt)

        y = self.height()
        dy = round((y-100)/2)
        self.legendScaleActor.SetTopBorderOffset(dy)
        self.legendScaleActor.SetBottomBorderOffset(dy)
        self.legendScaleActor.GetLeftAxis().SetSizeFontRelativeToAxis(False)
        self.legendScaleActor.GetLeftAxis().UseFontSizeFromPropertyOn()
        self.legendScaleActor.GetLeftAxis().GetLabelTextProperty().SetFontSize(10)
        self.legendScaleActor.Modified()
        self.renderWindow.Render()

if __name__ == ' __main__':
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

```

Any suggestion is appreciated~~~

My vtk version is 9.2.6.

---

<div class="post-metadata">

### Author: ![Paulo\_Carvalho](https://discourse.vtk.org/user_avatar/discourse.vtk.org/paulo_carvalho/32/370_2.png) [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [July 7, 2023, 5:34pm UTC](https://discourse.vtk.org/t/how-to-fix-the-font-size-length-for-vtklegendscaleactor/11874/2 "2023-07-07T17:34:33Z")

</div>

Hello,

Have you tried `SetAdjustLabels([True|False])` on `self.legendScaleActor` before setting the font size?

best,

PC

---

<div class="post-metadata">

### Author: ![zhang-qiang-github](https://discourse.vtk.org/user_avatar/discourse.vtk.org/zhang-qiang-github/32/2519_2.png) [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)
#### Post date: [July 10, 2023, 3:04am UTC](https://discourse.vtk.org/t/how-to-fix-the-font-size-length-for-vtklegendscaleactor/11874/3 "2023-07-10T03:04:55Z")

</div>

I have tried `SetAdjustLabels(False)`, but it doesn’t work.

I find the following `resizeEvent` works:

```
def resizeEvent(self, evt) -> None:
    super().resizeEvent(evt)
    y = self.height()
    dy = round((y-300)/2)
    # print(size, y, dy)
    self.legendScaleActor.SetTopBorderOffset(dy)
    self.legendScaleActor.SetBottomBorderOffset(dy)
    self.legendScaleActor.SetCornerOffsetFactor(1)

    relativeFontSize = 800/(self.width()+self.height())
    self.legendScaleActor.GetLeftAxis().SetLabelFactor(1.0)
    self.legendScaleActor.GetLeftAxis().SetSizeFontRelativeToAxis(False)
    self.legendScaleActor.GetLeftAxis().SetFontFactor(relativeFontSize)
    self.legendScaleActor.Modified()
    self.renderWindow.Render()

```