Looking for B4X GanttChart

Hello Community,

I am looking for a B4X GanttChart. If somebody has an idea and can help me please contact me.

Regards
h725

It seems to me that there is no such view.
You could use an Excel sheet (you will certainly find ready-made sheets on the web) and libraries:
jPOI 5 (b4j)
aPOI (b4a)

It seems to me that such a chart is easily created using B4X.
I did one of these (not B4X of course) in 1969.
If it isn't done yet, I'll give a go. Or maybe @klaus would like to. Or maybe you would like to.

I had begun to write one, as a custom view, but did never finish it.
If you are interested in I can send you the class as it is. It is a B4J project but designed cross-platform.
There is still a lot more to do, especially in the relations between the different tasks, how to draw them etc.
And the difficulty are the details, how deep to go.
The calendar is working.
And, I am not a specialist in these charts.

@klaus

Your chart design looks good. I like the ability to scroll horizontally and vertically.
Zooming in and out would also be a good feature in order to get "the big picture"

Although I have not seen it done with time frames smaller than a day, it should be possible by
setting the unit of time as a parameter (for example minutes in surgery, or hours in an assembly plant).

The computational parts of a Gantt chart are well-defined and mathematically simple.
It is essential to have an efficient and user-friendly method for creating the dataset that specifies the chart:

1. tasks/activities
2. optimistic, most likely, and pessimistic time estimates -> derived expected time
3. the dependencies between tasks (A cannot be started until X, Y, Z are finished)

I would design the App to work in landscape mode on the desktop computer as well as on devices, at least for tablets and larger phones.
Therefore I would use B4XPages, with one page dedicated to defining/editing a task, and another for displaying the chart, and a third for showing the dependencies in a network diagram. B4XPages would make it easy to go between these pages.

The network diagram (nodes and connectors) can show more information per node:
- The early start time (ES)
- The early finish time (EF)
- The late start time (LS)
- The late finish time (LF)
- The slack/float

In the time/Gantt chart and in the network diagram, the critical path should be highlighted.
I would save the task definitions in a standard .txt file, so it could be edited separately with Notepad++.
Each of the three sections could then be developed separately, using the prototype .txt file.

Microsoft has made a lot of money with "Microsoft Project", and it is a sophisticated, multi-user
project/program evaluation and review technique (PERT) tool, almost always required for submitting project proposals.

I think it would interesting to see how efficient and effective B4X would be in implementing something like it.
At least on a smaller scale: perhaps single user and perhaps with limited # of activities. It's strengths would be:
- cross platform
- modern, enlightened user interface
- ease of software development, maintenance, and updates
- supported by a large active community
- free, open source

William Lancee said:

It seems to me that such a chart is easily created using B4X.
I did one of these (not B4X of course) in 1969.
If it isn't done yet, I'll give a go. Or maybe @klaus would like to. Or maybe you would like to.

Click to expand...

In 1969 ???
With electronic computer ?

klaus said:

I had begun to write one, as a custom view, but did never finish it.
If you are interested in I can send you the class as it is. It is a B4J project but designed cross-platform.
There is still a lot more to do, especially in the relations between the different tasks, how to draw them etc.
And the difficulty are the details, how deep to go.
The calendar is working.
And, I am not a specialist in these charts.

View attachment 122753

Click to expand...

Congratulations on the work done so far
The topic (gantt) interests me a lot
And realizing the possibility to insert / modify the various tasks directly on the calendar, I think it would become a usable object in many applications
Is it possible to try the project already completed?

Sure, attached the B4J project.
I began this project when I read this thread Gantt Calender, but it seemed that were no real interest and I stopped it.
It was the first step, drawing the chart.
There are still some trouble when resizing.
Feel free to do whatever you want with it.

Hello Klaus,
that looks great. I downloaded the Demo, had a quick look at it and it goes into the direction I am looking for.

I know that I am not such a brain as you are, so I do not know if I am smart enough to develop a working, satisfied solution.

If it is OK for you Klaus, I would like to appeal to other users of this forum who might be interested in further development
of your GanttChart. I would like to underline that I would pay for a working solution. Maybe we come together.

Kind regards
h725

@amorosik

In 1969 ???
With electronic computer ?

Click to expand...

Wiki: The IBM System/360 (S/360) is a family of mainframe computer systems that was announced by IBM on April 7, 1964, and delivered between 1965 and 1978.

I worked as an Fortran programmer for a manufacturer of electric (not electronic) telephone switches. They had 280,000 numbered parts/subassemblies.
They needed Gantt charts to control the making of large telephone exchanges with deadlines. I'm sure IBM used PERT methods in creating the IBM360.

h725 said:

that looks great. I downloaded the Demo, had a quick look at it and it goes into the direction I am looking for.

Click to expand...

And what exactly are you looking for?
As already said, I am not a specialist in Gantt charts.
I made the project, you tested, as a kind of demonstrator to show what can be done.
I have carefully read the post of William Lancee and in my mind the 'easy' part is almost done.
But, now begins the 'hard work':
- What data is currently missing ?
- What exactly should be displayed and how ?
- What kind of dependencies between the different tasks are needed, how are these defined and how should they be displayed ?

As already said in some other threads, I am not looking for any job.
I do this because I have pleasure doing it, without any time constraint which is the advantage when you are retired.

I have worked a bit further with this project:
- It is now a B4XPages cross-platform project.
- Added task dependencies, currently only Finish to Start and Finish to Finish.
- Editing, Add, Insert, Update, Delete.
- Added cursor function with display.
A long click in the task table on the left side shows the edit window.

Tried
Very beautifull
Many thanks for sharing your work
(only for b4j > 9.30 (logColor..))

klaus said:

I have worked a bit further with this project

Click to expand...

very nice! Thanks

klaus said:

I have worked a bit further with this project:
- It is now a B4XPages cross-platform project.
- Added task dependencies, currently only Finish to Start and Finish to Finish.
- Editing, Add, Insert, Update, Delete.
- Added cursor function with display.
A long click in the task table on the left side shows the edit window.

Click to expand...

Wow !

Great.