Ritwesh wrote: "I want help in designing a Ruler UserControl."
Okay, now that we know there is no problem with creating a UserControl here, you can start to work on specifying the functionality and appearance required for your Ruler.
Here are some issues, from general to specific, that come immediately to mind:
general:
1. the overall architecture of your word-processor;
a. one document at a time in one main windows(SD), or multiple documents within a 'master-container' Form (MDI), or multiple documents accessible as Tabs in a 'master-container' Form (tabbed MDI) ?
Or, as in many modern big-applications, multiple documents in independent windows running in one application (SDI).
b. the design of your data-structures for how you keep track of document(s), Ruler settings, within Ruler settings tabs and tab-positions.
2. Visual presentation of Ruler(s)
a. within one document (one editor), can there be more than one Ruler displayed: can you set tabs independently within different sections of the document the user has selected using the Ruler, or in any other way ?
b. another way of asking this question ... assuming only one Ruler is displayed per document being edited ... is to ask if you can set tab-settings for any arbitrary user-selection of text within the document being edited.
c. note this question also goes to Ruler location: you could choose to have only one Ruler displayed per edited document, but ... on user action ... display it at the start of the Text the user has selected ... that's assuming you are allowing, as in 2.b, to have multiple tab settings within one document.
more specific:
1. the visual relationship of the Ruler to the document being edited:
a. is the Ruler a UserControl contained within the Document's container, or within a separate Window ? If it's in a separate window, can that window 'float,' or can it be 'docked' to specific sides of the document container, or does the ruler 'lock in place' at the top of the document ?
b. if the Ruler is a UserControl contained in the same container as the Document(s) being edited, then: same questions about location, and whether it can be moved, as in 1.a.
getting down to the code:
1. in all of the cases above, let's assume that the user moves some kind of ui element on the Ruler to set tabs, and those setting then take effect on either the entire document being edited, or some section of the document being edited.
a. what is your code strategy for the interaction of Ruler and document, and/or the interaction of Ruler and Application.
imho if you make a detailed outline of the functionality you require ... and don't require ... and then plan your data-structures, and then outline the interaction and event management strategy between Ruler and Document, and Document and Application, you'll be in a good place to deal with the specifics of Ruler design.
And, there are good resources here on CodeProject to help you, such as "Advanced Text Editor with Ruler by Aleksei Karimov."
Studying what's here on CP, and creating a prototype, and then asking questions here, as issues arise with your prototype, might be a good plan, while very general questions will probably not be as 'fruitful.'