# wx.lib.agw.rulerctrl¶

RulerCtrl implements a ruler window that can be placed on top, bottom, left or right to any wxPython widget.

## Description¶

RulerCtrl implements a ruler window that can be placed on top, bottom, left or right to any wxPython widget. It is somewhat similar to the rulers you can find in text editors software, though not so powerful.

RulerCtrl has the following characteristics:

• Can be horizontal or vertical;

• 4 built-in formats: integer, real, time and linearDB formats;

• Units (as cm, dB, inches) can be displayed together with the label values;

• Possibility to add a number of “paragraph indicators”, small arrows that point at the current indicator position;

• Customizable background colour, tick colour, label colour;

• Possibility to flip the ruler (i.e. changing the tick alignment);

• Changing individually the indicator colour (requires PIL at the moment);

• Different window borders are supported (wx.STATIC_BORDER, wx.SUNKEN_BORDER, wx.DOUBLE_BORDER, wx.NO_BORDER, wx.RAISED_BORDER, wx.SIMPLE_BORDER);

• Logarithmic scale available;

• Possibility to draw a thin line over a selected window when moving an indicator, which emulates the text editors software.

And a lot more. See the demo for a review of the functionalities.

## Usage¶

Usage example:

import wx
import wx.lib.agw.rulerctrl as RC

class MyFrame(wx.Frame):

def __init__(self, parent):

wx.Frame.__init__(self, parent, -1, "RulerCtrl Demo")

panel = wx.Panel(self)

text = wx.TextCtrl(panel, -1, "Hello World! wxPython rules", style=wx.TE_MULTILINE)

ruler1 = RC.RulerCtrl(panel, -1, orient=wx.HORIZONTAL, style=wx.SUNKEN_BORDER)
ruler2 = RC.RulerCtrl(panel, -1, orient=wx.VERTICAL, style=wx.SUNKEN_BORDER)

mainsizer = wx.BoxSizer(wx.HORIZONTAL)
leftsizer = wx.BoxSizer(wx.VERTICAL)
bottomleftsizer = wx.BoxSizer(wx.HORIZONTAL)
topsizer = wx.BoxSizer(wx.HORIZONTAL)

panel.SetSizer(mainsizer)

# our normal wxApp-derived class, as usual

app = wx.App(0)

frame = MyFrame(None)
app.SetTopWindow(frame)
frame.Show()

app.MainLoop()


## Events¶

RulerCtrl implements the following events related to indicators:

• EVT_INDICATOR_CHANGING: the user is about to change the position of one indicator;

• EVT_INDICATOR_CHANGED: the user has changed the position of one indicator.

## Supported Platforms¶

RulerCtrl has been tested on the following platforms:
• Windows (Windows XP);

• Linux Ubuntu (Dapper 6.06)

## Window Styles¶

No particular window styles are available for this class.

## Events Processing¶

This class processes the following events:

Event Name

Description

EVT_INDICATOR_CHANGED

The user has changed the indicator value.

EVT_INDICATOR_CHANGING

The user is about to change the indicator value.

RulerCtrl is distributed under the wxPython license.

Latest Revision: Andrea Gavana @ 19 Dec 2012, 21.00 GMT

Version 0.4

## Functions Summary¶

 ConvertPILToWX Converts a PIL image into a wx.Image. ConvertWXToPIL Converts a wx.Image into a PIL image. GetIndicatorBitmap Returns the image indicator as a wx.Bitmap. GetIndicatorData Returns the image indicator as a decompressed stream of characters. GetIndicatorImage Returns the image indicator as a wx.Image. MakePalette Creates a palette to be applied on an image based on input colour.

## Classes Summary¶

 Indicator This class holds all the information about a single indicator inside RulerCtrl. Label Auxilary class. Just holds information about a label in RulerCtrl. RulerCtrl RulerCtrl implements a ruler window that can be placed on top, bottom, left or right RulerCtrlEvent Represent details of the events that the RulerCtrl object sends.

### Functions¶

ConvertPILToWX(pil, alpha=True)

Converts a PIL image into a wx.Image.

Parameters
• pil – a PIL image;

• alphaTrue if the image contains alpha transparency, False otherwise.

Note

ConvertWXToPIL(bmp)

Converts a wx.Image into a PIL image.

Parameters

bmp – an instance of wx.Image.

Note

GetIndicatorBitmap()

Returns the image indicator as a wx.Bitmap.

GetIndicatorData()

Returns the image indicator as a decompressed stream of characters.

GetIndicatorImage()

Returns the image indicator as a wx.Image.

MakePalette(tr, tg, tb)

Creates a palette to be applied on an image based on input colour.

Parameters
• tr – the red intensity of the input colour;

• tg – the green intensity of the input colour;

• tb – the blue intensity of the input colour.