Working with Date data can be very tricky. I recently encountered an "Invalid argument to date encode", error while trying to update a SQLite database table.
This placed a value of 0000-00-00 into the date field of my SQLite table.
The getter function GetOneOffDateAsDate passes in a TDate which doesn't play nicely with FireDAC. Fortunately, the fix is quite simple. I found a fantastic explanation for this error on stackoverflow which states FireDAC expects DATE data type values to be a string in the fixed format of YYYY-MM-DD.
FireDAC Expects DATE data types to be strings formatted as YYYY-MM-DD
So I created another getter function to format the date data as a YYYY-MM-DD string. Problem solved!
I'm currently updating an old Delphi 5 Desktop VCL application to to Delphi 11.3 FMX. And one of the capabilities I want to provide is the ability to launch several webpages from within the application. I want to place a link in the main menu to my YouTube channel so customers can easily get to product videos. And there's also a link to my website in the Help > About box.
It was fairly straightforward the last time I did this using VCL because all I had to worry about was the Windows side of things. However, because I want this application to run on both Windows and macOS it presented a challenge.
The Delphi IDE won't recognize the Macapi namespace unless the target is set to MacOS 64-bit
Harry Stahl covers the COCOA API on pages 98-99 of his book Cross-Platform Development with Delphi. He also gives an example of how to use the NSWorkspace object of Macapi.Appkit. However, he doesn't show how to setup the uses clause.
I also found a fantastic reference on stackoverflow by David Heffernan that was written in 2015. However, there are two issues with Heffernan's if you are looking for a complete answer:
There is a reference to a blog post by Malcolm Groves called Opening files and URLs in default applications in OS X which is no longer available or accessible.
The example doesn't tell you you need to target the MacOS 64-bit platform before the IDE will recognize Macapi namespace..
The Delphi IDE won't recognize the Macapi namespace unless the target is set to MacOS 64-bit. Shame on me for not reading up on the Embarcadero docs. Wrapping my head around how to use the {$IFDEF MSWindows} and the {$IFDEF MACOS} was a little tricky But I eventually caught on.
After a couple hours of going back and forth with code that worked for Windows but didn't work for macOS. And code that worked for macOS but didn't work for Windows, I finally got Heffernan's example to work.
The next step was to extract the code out of the main form and place it into it's own unit. And that is the code I'm sharing with you today. I hope you find this helpful.
I'm in the process of converting an old Delphi 5 VCL application to Delphi 11 FMX. Yeah, I have Delphi 12 but I'm waiting for the first bug release before I start using it. Well, this morning I learned a valuable lesson. A lesson which stopped me dead in my tracks.
There's nothing stopping you from creating an already existing type!
I was making some refactoring changes to my code. I didn't realize I was about to make a huge mistake. I went plodding ahead pleased with the progress I was making and admiring the beautiful, refactored code I was creating. When boom... I renamed a type that stepped on a type already inside the System.UITypes unit.
There's nothing to stop you from creating an already existing type. Of course I didn't use the preview changes function. I just hit go!
I had defined my own enumerated type called TMyImageIndex. I decided to just simply call it TImageIndex. So, that's what I did using Refactor > Rename type TMyImageIndexCTRL+SHIFT+E
I knew I messed up when I saw way too much code show up in the results panel.
How dare Embarcadero define a type called TImageIndex
WTF. If it already existed the IDE should have prevented me or at least warned me. How dare Embarcadero define a type called TImageIndex.
Disclaimer: This post contains affiliate links, which means I may earn a small commission if you click through and make a purchase, at no extra cost to you. Your support helps keep this blog running – thank you!
I am a big fan of Harry Stahl's book "Cross-Platform Development with Delphi 10.2 & FireMonkey for Windows, MAC OS X (macOS) & Linux". I purchased this book in May 2021 and it has helped me several times as I'm porting my Zilch application from Delphi 5 VCL to Delphi 11 FMX.
I like to maintain RSS feeds of my favorite Delphi blogs. So, I went looking to see if Stahl has a blog I could add to my Outlook RSS Feeds. I found a couple of Stahl's websites. He does have a few blog posts but they are not easily converted into an RSS feed.
Note: Some links in this post are affiliate links, meaning I may receive a small commission if you make a purchase. This helps support my work – thank you for your understanding.
Disclaimer: This post contains affiliate links, which means I may earn a small commission if you click through and make a purchase, at no extra cost to you. Your support helps keep this blog running – thank you!
When it comes to Delphi, it's amazing how much I don't know, once knew but forgot, or just plain skipped over because it was too mind-boggling at the time. I took a break from reading Alister Christie's new book "Code Better in Delphi", which I purchased last night, to write this blog post.
While reading the bit on "refactoring", I realized how little refactoring I actually put into practice. Yes, I have Fowler's book, the second edition. And no, I haven't read it. I've thumbed through it a little in the past. I even tried looking for the "Introduce Explaining Variable" refactor Christie discusses on page 53 of his book. It turns out Fowler now calls it "Extract Variable". Keeping Fowlers "Refactoring" book on my desk, and referring to it often, is one way I am going to code better in Delphi.
It's amazing how much I don't know or once knew but forgot
I just started reading "The Observer Pattern" in Christie's book and had to stop. I bought "Head First Design Patterns" by O'Reilly, quite a few years ago. I have the 10th Anniversary edition with code examples in Java 8. My intent was to install Java on my machine and force myself to learn these patterns by following the code in the book. It didn't go so well. The authors do a great job using story to make learning fun. I just couldn't wrap my head around Java.
Christie has managed to reignite my desire to learn these patterns. I downloaded the Java source code. I plan to work my way through "Head First Design Patterns" pasting the Java source code into ChatGPT, and asking Chat to convert it to Delphi.
I will navigate through each pattern using this method. I will then revisit the same pattern in Primoz Gabrijelcic's book "Hand-On Design Patterns with Delphi". This is another way I'm going to learn to code better in Delphi.
Another way is to revisit the Model-View-Controller method of code separation. Here is a the MVC song from 2007 I just learned about today.
And I also want to implement "Interfaces".
Here's my list of how I will code better in Delphi:
Finish reading Christie's book
Practice refactoring often
Learn and implement design patterns
Discover and utilize ways to separate code concerns such as MVC or MVVM
Overcome my stumbling block of Interfaces
Use the comments below to share how you will code better in Delphi.
Note: Some links in this post are affiliate links, meaning I may receive a small commission if you make a purchase. This helps support my work – thank you for your understanding.
Although the demo and source code for this presentation is based on a mobile app, the concept Konopka presents is not just for mobile apps. It's actually a blueprint for creating any type of FMX app using Delphi.
Blueprint for Creating Delphi FMX Apps
I was compelled to write this blog for two reasons. The first stems from the fact that this is not just for mobile app development, it's for any FMX app development. And number two, the concept is simple, powerful, and elegant.
It doesn't matter whether you are brand new to Delphi or a seasoned Delphi veteran, if you get the opportunity to download and study an application built by Konopka, TAKE IT. You will learn so much. It's an opportunity to explore the mind of Konopka.
Konopka embodies the meaning of my favorite quote from Albert Einstein. "Make everything as simple as possible but not simpler."
I have just started to explore Personal Knowledge Management (PKM). Didn't know it was a thing until a few days ago. Obsidian (https://obsidian.md) seems to be one of the most popular tools being used. This tutorial is a couple years old but it's very good.
Just finished working out the logic for handling file logic:
File Open File New File Save File Save As
This assumes you are keeping track of the following:
Current Filename
Changes to file data
I've been wrestling with this one for a few days. And then it finally hit me. "Hey, Exit can be your friend."
Exit can be your friend
Within the last year, my thinking has been influenced by Jeff Patton and his book "User Story Mapping". At work I have been involved in many meetings/discussions where everyone is in agreement that we need to implement "Solution X". However, everyone has their own interpretation of what "Solution X" is.
This is part 1 in a series dedicated to Delphi FMX Desktop development. I am in the process of converting an old VCL application to FMX. When I first started playing around with FMX I was excited because one code base could serve up all different platforms; desktop, mobile, tablet. FMX also let's you create Windows, Mac OSX, Android, iPhone apps from that same single code base.
It wasn't until recently that I discovered one code base doesn't easily translate between desktop and mobile. So I am focused solely on creating one desktop code base for Windows and Mac OSX. This is a conscious choice on my part to stay in the desktop market.
Over the last 32 years I have had several Mac OSX users asking me when I would have a version of my software that would work on their computers. Delphi FMX will let me make this happen.
This leads to a series of questions:
What does the desktop market share look like?
How many new Mac customers will this bring me?
Is it worth the effort to create a desktop application for both Windows and Mac?
How does geographical location influence the decision?
I would like to thank the people at statcounter GlobalStats for providing the information in this post. Visit https://gs.statcounter.com/ for more information.
"The Whole World's Gone Mobile! Forget Desktop Development."
Let's start by looking at the Desktop vs Mobile vs Tablet market share. We are going to look at the past year and then look at the past ten years. This will show the huge growth in the mobile market.
Worldwide 1 Yr Mobile 60%Desktop 40%
Worldwide 10 Yr Mobile 16 → 60% ↑ Desktop 82 → 40% ↓
Looking at just this one graph you would think it's a waste of time to dive into the desktop market. On a world wide scale the mobile market has completely overtaken the desktop market. At first glance you might think, "Wow, it's not worth going after the desktop market. The whole world has gone mobile."
"I Might be Ignoring 50% of the Users!"
What about the United States? Does geography play any part in my decision to create a desktop application? After all, the majority of my customers come from the United States.
USA 1 Yr Mobile 46%Desktop 52%
USA 10 Yr Mobile 15 → 46% ↑Desktop 82 → 52% ↓
Because the majority of my customers are from the United States, and I'm only concerned with the Desktop market share, what do these numbers tell me?
Today, the Desktop market share in the United States is 52%. This tells me that 5 out of every 10 potential customers are desktop users. This also tells me that mobile use has skyrocketed over the past ten years, and my decision to only focus on desktop might be ignoring almost 50% of the users.
What about my decision to only focus on Windows and Mac OSX customers?
USA 10 Yr Windows 82 → 60% ↓OSX 16 → 30%↑
Here is what the Desktop Operating System landscape tells me looking at the past ten years. Windows is still the dominant operating system within the USA even though it has dropped 22%. On the other hand Mac OSX has almost doubled it's share of the market.
Overall, the prospects look good to invest some solid time and effort into creating a Desktop application that caters to both Windows and Mac users. As far as how many Mac OSX customers can I expect?
These numbers tell me I can expect about 5 new Mac OSX customers for every 10 new Windows customers. And that sounds pretty good to me.
Konopka does a fantastic job showing how to streamline the User Interface using Actions. This is a must see video from DELPHICON 2023.
He starts out showing the typical way of coding in Delphi by using onClick events on Buttons and Menus. He then shows how to build an ActionList from scratch, using Categories and Actions. He then ports all the onClick events to Action onExecute events. He also imparts the knowledge he's learned over the years as to why this is the best way to code a user interface. Absolutely brilliant.
Every time I watch Konopka give a presentation I learn something. It's amazing to watch a master demonstrate his craft.
If you've read some of my previous posts you know how much I've struggled to make the paradigm shift from being a top-down, procedural programmer to an OOP programmer. I've purchased several books on OOP. And one book series I thought would hold some promise are "The Object-Oriented Thought Process" books written by Matt Weisfeld. I have four different editions on my book shelf.
I struggle with OOP for several reasons. One very frustrating reason is the lack of Delphi/Pascal examples used by authors. Most of the code examples are written in Java, or C, or C# or some language other than Delphi/Pascal.
The last bullet point on page 3 of Weisfled's fourth edition, listed under the heading of "What's New in the Fourth Edition", states:
Expanded code examples, for certain chapters, in Java, C# .NET, VB .NET, and Objective-C available online on the publisher's website
No Object Pascal or Delphi examples!
No Object Pascal or Delphi examples. I reached out to Weisfeld asking if he might include Object Pascal examples and received a negative response.
I love Pascal. It's elegant. It's easy to read and understand. I've been using Pascal/Delphi since 1985. (2023-1985=38 years). Besides SQL, it's my main programming language. Ok, I confess, I did Active Server Pages (APS) and VB Script for about 10 years.
I've tried loading Java onto my machine so I could follow along and learn the OOP concepts but I just can't wrap my head around the Java syntax.
Today, I discovered the answer that works for me. ChatGPT!
I asked ChatGPT to convert the following Java code from page 24 of "The Object-Oriented Thought Process" to Delphi and the results were very hopeful.
public class IntSquare {
// private attribute
private int squareValue;
//public interface
public in getSquare (int value) {
squareValue = calculateSquare(value);
return SquareValue
}
//private implementation
private int calculation (int value) {
return Math.pow(value,2);
}
}
Here are the results returned from ChatGPT:
type
TIntSquare = class
private
FSquareValue: Integer;
function CalculateSquare(value: Integer): Integer;
public
function GetSquare(value: Integer): Integer;
end;
implementation
function TIntSquare.CalculateSquare(value: Integer): Integer;
begin
Result := value * value;
end;
function TIntSquare.GetSquare(value: Integer): Integer;
begin
FSquareValue := CalculateSquare(value);
Result := FSquareValue;
end;
end.
I know the results are not the indented and formatted code you would get from inside the IDE. This was my first attempt at using ChatGPT. I took several screen shots of my interaction with ChatGPT so I can show you what happened.
Here is my entire ChatGPT session:
Here is the final output from ChatGPT.
uses
System.Math;
type
TIntSquare = class
private
FSquareValue: Integer;
function GetSquareValue: Integer;
procedure SetSquareValue(const Value: Integer);
function CalculateSquare(value: Integer): Integer;
public
property SquareValue: Integer read GetSquareValue write SetSquareValue;
function GetSquare(value: Integer): Integer;
end;
implementation
function TIntSquare.CalculateSquare(value: Integer): Integer;
begin
Result := Round(Power(value, 2));
end;
function TIntSquare.GetSquare(value: Integer): Integer;
begin
SquareValue := CalculateSquare(value);
Result := SquareValue;
end;
function TIntSquare.GetSquareValue: Integer;
begin
Result := FSquareValue;
end;
procedure TIntSquare.SetSquareValue(const Value: Integer);
begin
FSquareValue := Value;
end;
end.
Influencing Human Behavior by H. A. Overstreet was published in 1925. I purchased an old hardcover copy of his book over a year ago because, some other book I was reading referred to it as a master work. Overstreet's book has been sitting on my oak book shelf, which was built by a very nice Mennonite man in Maryland, ever since it arrived.
I spent the weekend of November 26th and 27th entering all my "print books" into a software program called Calibre (https://calibre-ebook.com) which by the way, is mainly for managing E-books.
After saving the information from an ISBN import, I began reading. I stopped on page 12 after reading what Overstreet wrote about capturing one's attention using "The Kinetic Technique".
I stopped reading because this piece of wisdom so grabbed ahold of me, I wanted to let it seep into my mind.
Two days later on Tuesday morning at 1:45 AM I woke to a racing mind. "What book talked about a dot on the wall?" I kept searching, and searching my thoughts. Nothing.
"Ah, the influencing human behavior book."
Why was this so important that it woke me up? My website (read that as I) totally violated the principle of movement. Every page on my website has the same big-ass banner. I was making all my visitors (read that as potential customers) stare at a dot on the wall. How boring is that.
I jumped out of bed right then and there and started working on removing the dot from my website. It took me a few days, but I managed to get rid of that dot. But more importantly, I learned a valuable lesson from some ink that was printed nearly 100 years ago.
Thank you Mr. H. A. Overstreet. I can't wait to see what else of yours seeps into my mind.
Influencing Human Behavior - H. A. Overstreet (page 12)
I wanted a quick, down-and-dirty, reference to only those variables used by the Delphi IDE. Inside the IDE you can navigate to Tools > Options > IDE > Environment Variables. This will list all the Environment Variables currently in use. Those belonging to Delph and those outside of Delphi. However, that is not what I was looking for. I just wanted the Environment Variables specific to the Delphi IDE.
Step 1. I entered and ran the code from the above link. I then copied and pasted the contents of the memo to a separate text file called EnVars-Delphi-IDE.txt.
Step 2. I closed Delphi and ran the program again from the saved location. I then copied and pasted the contents of the memo to a file called EnVars-Without-Delphi-IDE.txt.
Step 3. I then navigated to the Delphi BDSBIN location and ran the Beyond Compare utility BCompareLite.exe. I did a text compare of EnVars-Delphi-IDE.txt and EnVars-Without-Delphi-IDE.txt looking only for the differences.
I simply copied all the text from the left-had side and saved it as EnVars-Delphi-IDE-Only.txt. And now I have my quick down and dirty list of Delphi IDE Environment Variables.
Beyond Compare is a fantastic tool written with Delphi. The lite version is included with your purchase of Delphi. For more information about Beyond Compare visit their website:
I've been playing around with the FMX StringGrid for the past three weeks. And I thought...
"Wouldn't it be nice if there was a way to automatically resize the column widths based on the values in each of the columns. Just like the way Excel works when you highlight the entire sheet and double-click the thin line between two columns."
In today's Delphi tip of the day I present a simple routine that evaluates the data in each of the column headings and the columns of each row to determine how wide to make the cells. And the best part is, it automatically adjusts all the columns widths in one go.
"Just like the way Excel works..."
It's fairly straight forward using two for loops. It loops through each column looking at every row and determining the width that column needs to be based on the data in each cell.
procedure AutoAdjustColumnWidths(const Grid : TStringGrid);
var
col : Integer; //Grid Column
w : single; //New Width
s : string; //Grid Column value
l : Integer; //Lenght of Grid Column value
row : Integer; //Grid Row
r : Single; //Result of TextWidth calculation
begin
for col := 0 to Grid.ColumnCount-1 do
begin
w := 0;
s := Grid.ColumnByIndex(col).Header;
l := length(s);
w := Grid.TextWidthToColWidth(l,s) * 1.05; //add a little padding
for row := 0 to Grid.RowCount-1 do
begin
s := Grid.Cells[col,row];
l := length(s);
r := Grid.TextWidthToColWidth(l,s) * 1.05; //add a little padding
if r > w then
w := r;
end;
Grid.Columns[col].Width := w;
end;
end;
I'm sure this can be improved upon so it only evaluates the first 50 or 100 rows. I'll leave that up to you to figure out.
The Hungry Brain points out how the brain works. The brain (your brain) is conditioned by past food choices and conditions you to make future choices. There are strong cues at play and the stronger ones win. Most of what happens is nonconscious. The author credits Daniel Kahneman, author of "Thinking, Fast and Slow" for the two brain systems. System 1 which is fast, effortless, intuitive, and nonconscious. System 2 which is slow, effortful, rational, and conscious. System 1 usually wins when it comes to food choices.
I was surprised by how food decisions are made in the brain and how the brain continuously reinforces those decisions. I was also stunned to discover how irrational our/my thinking can be. This supports the two systems Kahneman describes. For example; "The 1970 Stanford Marshmallow Experiment" gave children the option of one marshmallow now (which sat on a table right in front of them) or two marshmallows in 15 minutes. The kids were basically given a choice of a small reward now or a larger reward in the future. Most kids ate the one marshmallow right away. We/I tend to value the now more and the future not so much. This is a psychological trait called "delay discounting".
This book is a very technical read
I know I am one of those people who do/did not value my future self. I started smoking cigarettes when I was twelve. As an adult I smoked two and one-half packs of cigarettes a day. One day, after 32 years of smoking, I finally quite "cold turkey". As a smoker I totally discounted my future health. I've been smoke-free for 20+ years. For me, it's time to refocus on my future self and lose the weight. While a brown sugar cinnamon pop tart will definitely give me a 10 minute pleasure high it does not help my future self one bit.
This book is a very technical read. You could probably get away with reading only chapters 10 and 11. However, you would miss out on some of the little stories sprinkled throughout the other chapters.
This book has caused me to want to read two other books. The first book, which I purchased, is "Thinking, Fast and Slow" by Daniel Kahneman. I was originally introduced to Kahneman a few years back. I'm very much interested in storytelling and Kahneman links effective storytelling to emotions not rationale. So I am very interested in learning more about the two brain systems.
The second, which I checked out from the library is "Salt Sugar Fat" by Michael Moss. I've had a tacit understanding that processed foods are the new crack cocaine. I figure by reading this book two things will happen:
I will change my perspective on processed food and see them for what they truly are.
By learning exactly how food scientists tweak the salt, sugar, fat ratios every so slightly to keep their food irresistible, I will view these foods as traps, and see myself for what I really am... nothing more than a commodity (a tick mark on the balance sheet).
Please use the comments to give your recommendations for other, related books worth reading.
I purchased the book Delphi GUI Programming with FireMonkey by Andrea Magni on November 7, 2020. I dove in head first with great enthusiasm only to get derailed early on. It happened when I tried to follow the topic Understanding the Style Designer in chapter 2.
As someone who knows almost nothing about FireMonkey these four and one-half pages soured my learning and turned me against this book and it's author. I tried reaching out to the author directly and received a curt response basically telling me that the examples in his book were not meant to be step-by-step. From that moment on I let this book sit on the shelf and collect dust.
That was a foolish mistake on my part.
The Style Designer is a central part of FireMonkey and FMX. It is my opinion, that the author introduced this complex topic much too early in the book. It was presented with just a small smattering of knowledge and guidance. Leading me to three days of frustration because I could not make the Style Designer match what I saw in the book. The style designer is much too complex a topic to simply be glossed over in this fashion. A more fitting title for this topic would be First Glance at the Style Designer.
Don't Judge a Book by Only 4 Pages
If you are new to FMX and FireMonkey, and you want to get the most out of this book, I highly recommend you skip the topic Understanding the Style Designer in Chapter 2 (print: 34-38, pdf: 31-35). No understanding will happen. Instead, I recommend you watch this 50 minute YouTube video by Ray Konopka called Customizing Controls with FMX Styles.
After you have a better understanding of the FMX Style Designer, you may want to come back to the topic Understanding the Style Designer in this book.
You can best sum up my attitude about this book (and it's author) by the phrase "Don't judge a book by only 4 pages". I owe Magni an apology for holding a grudge against him because of 4 stinkin pages (and one email) in a book.
"Andrea, I'm sorry."
I finally picked up Magni's book (again) last week. Actually I did a search for "Live Bindings" of my digital Delphi books which lead me to pick up Magni's book of the shelf. I opened up to Chapter 4, Discovering Lists and Advanced Components to a huge surprise. The printed copy of my book went from page 104 to page 157. Pages 105 through 156 are missing.
I contacted Packt Publishing to let them know of the misprint. All is good, a new printed copy is on the way.
At this point I was committed and had to fall back on reading the PDF version of Magni's book. I recently had cataract surgery on both eyes so I was very hesitant. Reading PDF books and manuals always leads to eyestrain at best or headaches at worst. That's when I discovered you can customize the background and font colors of a PDF document. See my post "Tip of the Day - How to change the text color of a PDF document" for instructions on how to do this.
I'm only part way through Chapter 4: Discovering Lists and Advanced Components and so far, Magni had done a fairly descent job. I have downloaded the source code for this book. I find it very helpful to have Delphi up and running along side reading the customized PDF. I open the example projects and play along with the reading to get a better understanding.
Magni has done a a great job organizing the source code for this book. There is a separate chapter containing projects for each chapter. Each project within a given chapter has it's own folder. It is very well organized. The folders seem to be named intuitively. However, I find it very helpful to rename each folder and preface each folder name with the page number. That way I can quickly associate which project goes with with page or section of the book. As a plus, any un-numbered folders means I haven't opened that project and most likely haven't read that section of the book in detail.
I'm not sure when or if I will get finished with Magni's book. I'm just glad I overcame my stubbornness and opened his book back up again. I do know I have a need to and look forward to learning the following:
Chapter 4 Discovering Lists and Advanced Components
ListBox
ListViews
Treeviews
Grids
Chapter 5 Using FireDAC in FMX Applications
Chapter 6 Implementing Data Binding
Chapter 7 Understanding FMX Style Concept
Chapter 8 Divide and Conquer with TFrameStand (Maybe)
I was reading Andrea Magni's book Delphi GUI Programming with FireMonkey and realized I am missing pages 105-156. Packt Publishing is having a new print copied sent to me. Anyway, the PDF copy of the book is 100% complete.
I've always dreaded having to read PDF books for two reasons:
I don't like the way the pages jump from one page to another
The standard black text on a white background hurts my eyes and makes them tired.
I recently discovered two things you can change about PDF books (documents) that have made a huge difference for me.
One is smooth scrolling. I thought that all pdf's jumped from the bottom of the page to the top of the next page. Not true. This is a setting.
The second thing I discovered is the ability to change the color of the text within a pdf document. The standard black text on white background rally hurts my eyes. By changing the background and text color it is much more enjoyable to read.
This video shows you how to set smooth scrolling and change the text and background colors within a PDF document.
I'm in the process of porting over an old VCL application to FMX. At this time I'm only concerned with creating a desktop application that will run on Windows and macOS. One of the VCL features I like is the ability to set the forms minimum width and height properties. This prevents the user from making the application ridiculously small and unusable.
With a VCL application this is accomplished by simply entering the desired values in the MinHeight and MinWidth propertiesof the forms Constraints. The example below sets the VCL forms minimum height to 540 and the minimum width to 720.
Unfortunately, these properties do not exist within FMX Muilti-Device applications. In order to impose size constraints in FMX you have to write some code in the OnResize event handler.
The simplest way to accomplish this would be to right some code similar to this:
const
MinW = 720;
MinH = 540;
begin
if Width < MinW then Width := MinW;
If Height < MinH then Height := MinH;
end;
This works. However it produces a horrible flickering effect when you continue to drag the mouse inside the boundaries specified within the OnResize event handler.
Windows Form Constraints with Flickering
What about the macOS? Does it flicker? The answer is no. The macOS respects the size constraints with no flickering issue:
macOS Form Constraints no Flickering
So the issue only happen on Windows PC's.
I may be oversensitive here but I do not like this flickering at all. In my mind it gives the sense of an unprofessional appearance. Some end users may not care one bit about this and that's fine. However, it really bugs me. I want to prevent this from happening.
So I went looking for a solution and found one on stackoverflow. The code simulates a mouseUp event if the cursor moves inside the boundaries.
Windows Form Constraints with No Flickering
This is accomplished by making a Windows API Mouse Event call inside the OnResize event handler. It's not perfect but it does prevent the flickering from happening.
Add this to the Uses clause Winapi.Windows
Modify the onResize event handler to simulate the mouseUp event.
const
MinW = 720;
MinH = 540;
begin
if Width < MinW then
begin
Width := MinW;
mouse_event(MOUSEEVENTF_ABSOLUTE or MOUSEEVENTF_LEFTUP, 0, 0, 0, 0);
end;
If Height < MinH then
begin
Height := MinH;
mouse_event(MOUSEEVENTF_ABSOLUTE or MOUSEEVENTF_LEFTUP, 0, 0, 0, 0);
end;
end;
This code works great! It stops Windows PC's from flickering. However, we are not done yet. We have to wrap special tags around the Windows Only code so it is ignored by the macOS.
I know this year isn't over yet but I'm pretty sure I won't make a bigger mistake between now and January 1st.
Mike has been selling a software product written in Turbo Pascal & Delphi for 30 years. Mike's software was mentioned on the television show Good Morning America. Mike got very excited. Mike updated his website making the 30-second Good Morning America television segment center stage. Nobody cares Mike's software got mentioned on television (except Mike). Mike turned off potential customers who visited his website. Mike's sales dropped. Mike's a jerk. Don't be like Mike.
This was one of the hardest lessons I learned.
I was so sure my would-be customers would feel just as excited about my software getting praise on national television as me. So sure in fact, that I posted a video of my software getting mentioned front and center on my website. And not just on the home page... but on every page.
Wrong!
People don't care about me. People care about themselves.
People don't care about you. People care about themselves.
It was Saturday morning, August 21, 2021. I was sitting on the couch in my living room watching cartoons with my granddaughter. And my phone dinged. I received an notification of a sale. A few minutes later another ding, another sale. I checked the real-time website stats and to my surprise there were 53 visitors on my site all at the same time.
I started googling trying to figure out what was causing this frenzy of visitors to my website. And by luck I found a video segment that had just aired on the Good Morning America television show.
The total segment was about 4 minutes long. The last 35-40 seconds is where my software ZilchWorks was mentioned. So I trimmed the video down to the last 40 seconds because that's the part that talked about my software. Proof again that people only care about themselves. Why else would I have trimmed down this video.
I then retooled my entire website and made this "Look what I can do" video front and center. I foolishly thought this would drawn in website visitors.
Lessons Learned:
People don't care about you. They care about themselves.
