TBitBtn failed on me
lazarus / 39-Graphics

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ArminLinder · 2017-02-14 21:23

Guys,

tonight the IT devil is running free. Whatever I touch, miraculously
fails. Even very basic things. And I cannot figure out why.

Problem (already isolated from project): I have an application with a
form, and a TBitBtn on it, width=45, height=45.

I have a png, width = 180 (45x4), height = 45, 32 Bit colour depth
(also tried with 24, no difference), with 4 different glyphs on it
(for testing, I made 4 squares, 45x45 pixels each, in different
colors).

I habe assigned the png to the "Glyph" property, and set NumGlyphs to
4. Everything else on the defaults, so BitBtn is enabled= true. The
preview of the image in the glyph's load dialog looks fine.

When I run this project, always and only the first of the four glyphs
is displayed, if I hover over or click onto the button. The button
works OK, goes down and up on click. If the button is disabled, also
no glyph is displayed as well, but some blueish placeholer.

I did also try to convert the png to jpg and bmp, same problem: I can
load the glyph image, preview is fine, but if I run the project I do
always get the first image on the button.

BUT:  the project exe runs fine on Windows 10, while it fails on
Windows 7 (no re-compile!). And I am (almost) sure I had this thing
running well on Windows 7 this morning.

(Gnarl)

Anyone having an idea, why this can happen?

Armin.

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ArminLinder · 2017-02-14 21:40

This is the project source. Could not attach it to the previous post
for no obvious reason - the Devil never sleeps, you know ...

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Bart · 2017-02-14 21:57

Quote from: Nimral on February 14, 2017, 10:23:38 pmI have assigned
the png to the "Glyph" property, and set NumGlyphs to 4.

Quote from
http://docwiki.embarcadero.com/RADStudio/Berlin/en/Bitmap_Buttons:
"Bitmap buttons can have 3 states: up, down, and held down. Set the
NumGlyphs property to 3 to show a different bitmap for each state."

Not sure if this applies to Lazarus as well, too lazy to look it up.

Bart

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ArminLinder · 2017-02-15 06:34

That's what documenations are for: the devil   uses them to seed
confusion. From the same doc:

http://docwiki.embarcadero.com/Libraries/Berlin/en/Vcl.Buttons.TBitBtn
.Glyph

There it says: four pictures.

Nevertheless I gave it a try, I cropped my bitmap to 3x45 and set
NumGlyphs to 3 --> no change, on W7 still only Glyph #1 is displayed.

And there is a Lazarus doc which says up to 5(!) images are supported,
in addidion to Delphi's 4 a "Hot" (also called Hover or MouseOver)
Icon was added, so I tried with a 5 icon bitmap and NumIcons=5 as well
... no progress.

Thanks though,

Armin.

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ArminLinder · 2017-02-15 08:40

After further testing, I came to the conclusion that this is a bug in
Lazarus. Seems to affect Windows XP and WIndows 7,but not Windows 10.
On Delphi XE7, the glyph works correctly.

I'll file a bug now.

(Bug filed: http://bugs.freepascal.org/view.php?id=31392)

Armin.

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ArminLinder · 2017-02-15 20:10

Solved!

With the help of Bart Broersma, I made progress: the malfunction
arises only, when Windows Themes are turned off. It doesn't have
anything to do with the OS version.

I was unaware of this effect, since in Delphi RAD Studio the BitBtn
works regardless of whether Windows Themes are turned on or off.

Armin.