XMSETCOLORCALCULATION(3)

💖 XmSetColorCalculation 💖

okay bestie, so you know how the manual name is XmSetColorCalculation(library call)? yeah. that's her. that's the girl we're talking about today, and she is lowkey the reason your widgets don't look like sad grey rectangles. let's get into it 🎀

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✨ NAME ✨

XmSetColorCalculation — a function to set the procedure used for default color calculation 🎨✨

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🦋 SYNOPSIS 🦋

#include <Xm/Xm.h>
XmColorProc XmSetColorCalculation(
XmColorProc color_proc);

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🌸 DESCRIPTION 🌸

okay so here's the tea: XmSetColorCalculation sets the procedure that calculates your default colors. like, the whole vibe of your app's palette? this function is the one holding the aux cord 🎧

this procedure is used to calculate the foreground, top shadow, bottom shadow, and select colors — all based on a given background color. so basically you hand it a background and it manifests the rest of the fit 💅

and if you call it with an argument of NULL? it restores the default procedure used to calculate colors. we love a reset button, no cap 🙌

• color_proc — specifies the procedure to use for color calculation. (that's it. that's the whole job. iconic.)

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🧚 the XmColorProc type, explained (iykyk) 🧚

here's what the XmColorProc type that XmSetColorCalculation uses actually looks like:

void (*color_proc) (background_color, foreground_color, select_color, top_shadow_color,
bottom_shadow_color)
        XColor  *background_color;
        XColor  *foreground_color;
        XColor  *select_color;
        XColor  *top_shadow_color;
        XColor  *bottom_shadow_color;
(void)

okay so what's happening here 👀

this specifies the procedure used to calculate default colors. the procedure gets passed a pointer to an XColor structure representing the background color. and bestie, listen: the pixel, red, green, and blue members of this structure are filled in with values that are valid for the current colormap. they're pre-loaded. main character energy ✨

then the procedure is passed pointers to XColor structures representing the foreground, select, top shadow, and bottom shadow colors to be calculated. the procedure calculates and fills in the red, green, and blue members of these structures. just those three, okay? not the pixel.

⚠️ important bestie moment: the procedure should not allocate color cells for any of these colors. do not do it. that is not the assignment. periodt 💀

and here are the args, one by one:

• background_color — specifies the background color.
• foreground_color — specifies the foreground color to be calculated.
• select_color — specifies the select color to be calculated.
• top_shadow_color — specifies the top shadow color to be calculated.
• bottom_shadow_color — specifies the bottom shadow color to be calculated.

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👑 RETURN 👑

returns the color calculation procedure that was used at the time this routine was called. so it hands you back the old one, like "here's what you had before, don't lose it 🫶". so thoughtful.

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🌈 RELATED 🌈

• XmChangeColor(3)
• XmGetColors(3)
• XmGetColorCalculation(3)

go read those too, bestie, they're all in the same friend group 💜

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and that's the whole page, angel 💖 this was XmSetColorCalculation(library call) — yes the title shows up twice, she's got range — brought to you by the Xm library, and honestly? she ate. mwah. 🎀💅✨