Welcome!

Microsoft Cloud Authors: Pat Romanski, Liz McMillan, Lori MacVittie, Elizabeth White, Yeshim Deniz

Related Topics: PowerBuilder, Microsoft Cloud

PowerBuilder: Article

Dancing Checkboxes

Writing a window that will allow you to “set the day of the week”

Normally I write columns about the DataWindow or Appeon. This month though I ran into an interesting little logic problem and when I solved it I realized it was really a nice piece of code so, even though it is not in my normal genre I thought I'd share it.

I was tasked with allowing the user to pick a combination of days of the week with these specifications.

  1. The user may select no more than three days prior to today.
  2. The user may select no more than three days in the future.
  3. The user may not have both prior and future dates in the same group
  4. If there are not three days in the past available in this week then the week "wraps." That is to say, if the day is Monday then you only have Sunday as a past day in the week, but for our purposes Saturday and Friday would be considered past days of the same week.
  5. Repeat rule 4 for future days.

It was actually rules 4 and 5 that gave me fits. If it hadn't been for those rules this would be a straightforward thing. Rules 4 and 5 meant that I had to get really creative. Rules 4 and 5 stem from the fact that this is a means of selecting days for a report. The report may be historical or projected (future). They are only interested in four days at any time. Those four days being the current day and either up to three days in the past or future. In fact they aren't necessarily interested in today. They may only choose last Tuesday - as long as last Tuesday was not farther than three days in the past.

For the purposes of this article I am going to write a window that will allow you to "set the day of the week" so that we can test.

I created a small window and put seven checkboxes thereupon. They were named, predictably, cbx_Sunday, cbx_Monday, cbx_Tuesday, cbx_Wednesday, etc. Each of the checkbox controls were carefully sized to be just a little bit bigger than the text. I put each of them inside a group box that had the text attribute removed so it just looked like a 3D box. Then I aligned them horizontally, see Figure 1.

Here is where the problems with rules 4 and 5 become apparent. If today is Wednesday then everything looks and acts fine. We could have the previous three days selected with no problem. Look at Figure 2.

We are supposing in Figure 2 that today is June 25, 2012. We have Monday checked. Also Sunday is checked and that would be June 24. Sunday and Saturday are both checked and according to our rules they would be June 23 and June 22. However, if you look at Figure 2, does it appear that Saturday and Sunday are in the past? No, of course it doesn't. I found this to be deceptive and prone to user error. Clearly some creativity is required here.

My first idea was to let the checkboxes be moved so that the middle day of the seven was always in the middle. That way the days on the left are always in the past and the days on the right are always in the future. For my first attempt I made all the controls equal size, as big as the biggest, and then it was easy to just move them around.

The problem with this is that the display looked horrible. There was more space between Monday and Tuesday than Wednesday and Thursday. It just didn't look good, see Figure 3.

Compare the space between Wednesday and Thursday to the space between Friday and Saturday. Clearly this is inconsistent. We needed a better idea.

I went back to the original idea of having the controls just a little bit bigger than they needed to be. Now I couldn't use fixed positions for the x coordinate. I needed to generate the x coordinates. That meant that I could start where cbx_Sunday.x is but after that I need to put the second one at cbx_Sunday.x + cbx_Sunday.width + li_some_small_buffer.

To do this I created an instance array of checkboxes (did you know you could do that?). Here is what it looks like:

W_main Instance Variables

checkbox icbx_days[7]

The icbx_days array will hold the days of the week in their proper order. If today is Friday then icbx_days[1] will be the checkbox for cbx_Tuesday. We will handle that in the open event. Let's take a look at the open event, which is the core of this whole thing.

First we need an array that will be the checkboxes in the order in which they will eventually be needed. I named that lcbx.

We can find out the day of the week with the dayNumber function passing today() as an argument. The fourth element of icbx_days should always be today, so we start from there. We set the background color since we want it obvious that is today. After that we set the fourth element (middle) of the instance variable icbx_days to be the checkbox in the local array that is at the day number.

If this isn't clear, go to the listing and look at the four lines under the comment //Today is in the middle. That should make sense to you.

After that there is series of code segments where I decrement the li_index variable, loop it around if needed, then just set the checkbox in the local array to the instance variable. In essence I'm loading the instance array with the checkboxes in the order that I need to display.

You might want to look about halfway down these segments for the comment that says // Now Tomorrow. That's where I start loading the future days.

Finally there is a for-next loop that moves the checkboxes to the proper places.

It is Monday when I wrote this column so if you look at Figure 4 you will see the final result.

W_main.open
// Move the checkboxes to the proper sequence
int li_cbx_x_positions[7], li_index, li_y = 112
long ll_start, ll_delta, ll_count, ll_width

checkbox lcbx[]
lcbx = {cbx_sunday, cbx_monday, cbx_tuesday, cbx_wednesday, cbx_thursday, cbx_friday, cbx_saturday}

// Today is in the middle
li_index = dayNumber(today())
lcbx[li_index].backcolor = rgb(178, 34, 34)
lcbx[li_index].textcolor = rgb(255, 255, 255)

icbx_days[4] = lcbx[li_index]

// Let's do yesterday
li_index --
if li_index < 1 then li_index = 7
icbx_days[3] = lcbx[li_index]

// Now the day before yesterday
li_index --
if li_index < 1 then li_index = 7
icbx_days[2] = lcbx[li_index]

// Now the day before that
li_index --
if li_index < 1 then li_index = 7
icbx_days[1] = lcbx[li_index]

// Now tomorrow
li_index = dayNumber(today()) + 1
if li_index > 7 then li_index = 1
icbx_days[5] = lcbx[li_index]

// Now tomorrow
li_index ++
if li_index > 7 then li_index = 1
icbx_days[6] = lcbx[li_index]

// Now the last day
li_index ++
if li_index > 7 then li_index = 1
icbx_days[7] = lcbx[li_index]

//Now we move them to the right places
ll_delta = 30
ll_start = cbx_sunday.x
ll_width = cbx_wednesday.width

for ll_count = 1 to 7
icbx_days[ll_count].move(ll_start, li_y)
ll_start += icbx_days[ll_count].width + ll_delta
next

Download source code here.

More Stories By Richard (Rik) Brooks

Rik Brooks has been programming in PowerBuilder since the final beta release before version 1. He has authored or co-authored five books on PowerBuilder including “The Definitive DataWindow”. Currently he lives in Mississippi and works in Memphis, Tennessee.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


IoT & Smart Cities Stories
Machine learning has taken residence at our cities' cores and now we can finally have "smart cities." Cities are a collection of buildings made to provide the structure and safety necessary for people to function, create and survive. Buildings are a pool of ever-changing performance data from large automated systems such as heating and cooling to the people that live and work within them. Through machine learning, buildings can optimize performance, reduce costs, and improve occupant comfort by ...
René Bostic is the Technical VP of the IBM Cloud Unit in North America. Enjoying her career with IBM during the modern millennial technological era, she is an expert in cloud computing, DevOps and emerging cloud technologies such as Blockchain. Her strengths and core competencies include a proven record of accomplishments in consensus building at all levels to assess, plan, and implement enterprise and cloud computing solutions. René is a member of the Society of Women Engineers (SWE) and a m...
Poor data quality and analytics drive down business value. In fact, Gartner estimated that the average financial impact of poor data quality on organizations is $9.7 million per year. But bad data is much more than a cost center. By eroding trust in information, analytics and the business decisions based on these, it is a serious impediment to digital transformation.
DXWorldEXPO LLC announced today that Ed Featherston has been named the "Tech Chair" of "FinTechEXPO - New York Blockchain Event" of CloudEXPO's 10-Year Anniversary Event which will take place on November 12-13, 2018 in New York City. CloudEXPO | DXWorldEXPO New York will present keynotes, general sessions, and more than 20 blockchain sessions by leading FinTech experts.
Apps and devices shouldn't stop working when there's limited or no network connectivity. Learn how to bring data stored in a cloud database to the edge of the network (and back again) whenever an Internet connection is available. In his session at 17th Cloud Expo, Ben Perlmutter, a Sales Engineer with IBM Cloudant, demonstrated techniques for replicating cloud databases with devices in order to build offline-first mobile or Internet of Things (IoT) apps that can provide a better, faster user e...
Bill Schmarzo, Tech Chair of "Big Data | Analytics" of upcoming CloudEXPO | DXWorldEXPO New York (November 12-13, 2018, New York City) today announced the outline and schedule of the track. "The track has been designed in experience/degree order," said Schmarzo. "So, that folks who attend the entire track can leave the conference with some of the skills necessary to get their work done when they get back to their offices. It actually ties back to some work that I'm doing at the University of ...
Charles Araujo is an industry analyst, internationally recognized authority on the Digital Enterprise and author of The Quantum Age of IT: Why Everything You Know About IT is About to Change. As Principal Analyst with Intellyx, he writes, speaks and advises organizations on how to navigate through this time of disruption. He is also the founder of The Institute for Digital Transformation and a sought after keynote speaker. He has been a regular contributor to both InformationWeek and CIO Insight...
Rodrigo Coutinho is part of OutSystems' founders' team and currently the Head of Product Design. He provides a cross-functional role where he supports Product Management in defining the positioning and direction of the Agile Platform, while at the same time promoting model-based development and new techniques to deliver applications in the cloud.
Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settlement products to hedge funds and investment banks. After, he co-founded a revenue cycle management company where he learned about Bitcoin and eventually Ethereal. Andrew's role at ConsenSys Enterprise is a mul...
In his session at 21st Cloud Expo, Raju Shreewastava, founder of Big Data Trunk, provided a fun and simple way to introduce Machine Leaning to anyone and everyone. He solved a machine learning problem and demonstrated an easy way to be able to do machine learning without even coding. Raju Shreewastava is the founder of Big Data Trunk (www.BigDataTrunk.com), a Big Data Training and consulting firm with offices in the United States. He previously led the data warehouse/business intelligence and Bi...