A sparse array input control

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Introduction

You may have run into the need of entering sparse values for a two dimensional array. The most common case is that of entering time ranges for each day of the week when a person is available for work.

Searching through CP, I found some interesting work by ClearlyDotNet (see "A Time-Of-Day Picker control"), which provides such functionality, except that by returning TimeSpans, would not allow for a generic control that allows for the entry of non-time values.

What I needed was a control that generated generic output that could be saved to a file, and restored as needed, as well as the ability to dynamically change the row and column definitions while keeping any selected cell that applies in the new row/column set.

Having sometime on my hands, I decided to write my own. This article is the result of my labors, and it is placed here at CP as part of my repayment for some good ideas that I have gotten from other submissions. You can use the source as you wish, just remember that it is public domain, so keep it that way!

Using the code (programmer's view)

You can adapt the control to meet your requirements by changing the following properties:

<SparseArray>
<Entry>
  <Row>textfromRowsproperty</Row>
  <Col>textfromColsproperty</Col>
</Entry>
<Entry>
  <Row>textfromRowsproperty</Row>
  <Col>textfromColsproperty</Col>
</Entry>
<Entry>
  <Row>textfromRowsproperty</Row>
  <Col>textfromColsproperty</Col>
</Entry>
<Entry>
  <Row>textfromRowsproperty</Row>
  <Col>textfromColsproperty</Col>
</Entry>
</SparseArray>

All of the properties are available at design time, and changes are shown immediately.

The control fires one event TextChanged whenever the user changes the selected cells. This event does not fire if the Text property is set programmatically.

Using the code (end user's view)

The end user selects cells by clicking on them. He/she can also select ranges by clicking on the starting cell and then dragging the cursor to the end cell. Note that selecting regions causes the reversal of cell state for those cells already selected.

Points of Interest

The code was developed under Visual Studio 2003, and Framework 1.1. My intention is to share the code so all can use and maybe learn a bit from it. Do not assume that the code is free from bugs, as it was done in a few hours, but feel free to make any changes and/or corrections that you feel appropriate.

History

Released to the world December 20, 2004.