Re: hildon_color_button custom colors issue
On Wed, Apr 16, 2008 at 12:40 PM, Aniello Del Sorbo [EMAIL PROTECTED] wrote: Anyway.. the first issue below happened because I was running Xournal from root in an SSH remote shell. Thus, probably, colormaps were wrong. Running it the usual way (from the Menu) fixed a bit things. The GdkColor returned by the hildon color chooser was, when drawn on the canvas, slightly different from the one showed in the button itself. I think it looked darker. After digging a bit I figured out that the GdkColor RGB values where RGB16 (guint16) while I needed the RGB8 format (for the fill-color-rgba property). Thus, I had to first divide red, green and blue by 255 before putting them into a single guint value (RGBA) in the form of 0xRRGGBBAA. guint rgba = GNOME_CANVAS_COLOR_A (color-red / 255.0, color-green / 255.0, color-blue / 255.0, alpha) Further corrected, the divisor should not be 255 but 257 (0x101) instead. Otherwise the reduction from RGB16 to RGB8 does not work. RGB16 is in the form: 0x i.e. values range from 0 to 65535 RGB8 is in the form 0xRRGGBB i.e. values range from 0 to 255. Sorry if this is stuff people already know, but I am new to it and couldn't find much about it. -- anidel ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: hildon_color_button custom colors issue
I think that is still incorrect. You should divide by 256. That is exactly equivalent to shifting the bits to the right by 8. That moves the bits you want into the byte you need. -- Allen Brown http://brown.armoredpenguin.com/~abrown On Wed, Apr 16, 2008 at 12:40 PM, Aniello Del Sorbo [EMAIL PROTECTED] wrote: Anyway.. the first issue below happened because I was running Xournal from root in an SSH remote shell. Thus, probably, colormaps were wrong. Running it the usual way (from the Menu) fixed a bit things. The GdkColor returned by the hildon color chooser was, when drawn on the canvas, slightly different from the one showed in the button itself. I think it looked darker. After digging a bit I figured out that the GdkColor RGB values where RGB16 (guint16) while I needed the RGB8 format (for the fill-color-rgba property). Thus, I had to first divide red, green and blue by 255 before putting them into a single guint value (RGBA) in the form of 0xRRGGBBAA. guint rgba = GNOME_CANVAS_COLOR_A (color-red / 255.0, color-green / 255.0, color-blue / 255.0, alpha) Further corrected, the divisor should not be 255 but 257 (0x101) instead. Otherwise the reduction from RGB16 to RGB8 does not work. RGB16 is in the form: 0x i.e. values range from 0 to 65535 RGB8 is in the form 0xRRGGBB i.e. values range from 0 to 255. Sorry if this is stuff people already know, but I am new to it and couldn't find much about it. -- anidel ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: hildon_color_button custom colors issue
Hi, this may help other people when working with RGBA values. I did indeed solved the problem. Anyway.. the first issue below happened because I was running Xournal from root in an SSH remote shell. Thus, probably, colormaps were wrong. Running it the usual way (from the Menu) fixed a bit things. The GdkColor returned by the hildon color chooser was, when drawn on the canvas, slightly different from the one showed in the button itself. I think it looked darker. After digging a bit I figured out that the GdkColor RGB values where RGB16 (guint16) while I needed the RGB8 format. Thus, I had to first divide red, green and blue by 255 before putting them into a single guint value (RGBA) in the form of 0xRRGGBBAA. guint rgba = GNOME_CANVAS_COLOR_A (color-red / 255.0, color-green / 255.0, color-blue / 255.0, alpha) Is that the correct explanation ? -- anidel On Tue, Apr 15, 2008 at 8:16 PM, Aniello Del Sorbo [EMAIL PROTECTED] wrote: I reply to myself. I was testing the app running it from a remote SSH (root) and not from the user's Menu. It works. Thanks anyway. Aniello On Tue, Apr 15, 2008 at 5:50 PM, Aniello Del Sorbo [EMAIL PROTECTED] wrote: Hi, while porting Xournal to Maemo I decided to give it as much hildonization is possible. Base xournal uses only a bunch of predefined colors (something like 9 or 10 colors). I decided to use the hildon_color_button widget to give the user a much wide choice of colors. I get the GdkColor from the color button and have to convert it in RGBA because Xournal only works with those values (passing fill-color-rgba to the canvas items). It does this, I think, for being able to make a highlighter tool available in different colors (by making use of the alpha channel). anyway, I convert the GdkColor to RGBA using the macro: GdkColor *color; // read from the hildon_color widget guint alpha = 0xFF; // no transparency guint rgba = GNOME_CANVAS_COLOR_A (color-red, color-green, color-blue, alpha) and then use it wherever it is needed. This works for the predefined colors in the color chooser dialog. But if I choose my own custom color it does not. If I use the GdkColor as is (thus passing fill-color-gdk to the canvas items), it works, but I can't use the alpha channel (can I ?). If I convert this custom color to RGBA with the given macro, it paints in a totally different color. Is this some issue with the colormap ? Is GNOME_CANVAS_COLOR_A not good for this ? Any other hints ? -- anidel -- anidel -- anidel ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
hildon_color_button custom colors issue
Hi, while porting Xournal to Maemo I decided to give it as much hildonization is possible. Base xournal uses only a bunch of predefined colors (something like 9 or 10 colors). I decided to use the hildon_color_button widget to give the user a much wide choice of colors. I get the GdkColor from the color button and have to convert it in RGBA because Xournal only works with those values (passing fill-color-rgba to the canvas items). It does this, I think, for being able to make a highlighter tool available in different colors (by making use of the alpha channel). anyway, I convert the GdkColor to RGBA using the macro: GdkColor *color; // read from the hildon_color widget guint alpha = 0xFF; // no transparency guint rgba = GNOME_CANVAS_COLOR_A (color-red, color-green, color-blue, alpha) and then use it wherever it is needed. This works for the predefined colors in the color chooser dialog. But if I choose my own custom color it does not. If I use the GdkColor as is (thus passing fill-color-gdk to the canvas items), it works, but I can't use the alpha channel (can I ?). If I convert this custom color to RGBA with the given macro, it paints in a totally different color. Is this some issue with the colormap ? Is GNOME_CANVAS_COLOR_A not good for this ? Any other hints ? -- anidel ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: hildon_color_button custom colors issue
I reply to myself. I was testing the app running it from a remote SSH (root) and not from the user's Menu. It works. Thanks anyway. Aniello On Tue, Apr 15, 2008 at 5:50 PM, Aniello Del Sorbo [EMAIL PROTECTED] wrote: Hi, while porting Xournal to Maemo I decided to give it as much hildonization is possible. Base xournal uses only a bunch of predefined colors (something like 9 or 10 colors). I decided to use the hildon_color_button widget to give the user a much wide choice of colors. I get the GdkColor from the color button and have to convert it in RGBA because Xournal only works with those values (passing fill-color-rgba to the canvas items). It does this, I think, for being able to make a highlighter tool available in different colors (by making use of the alpha channel). anyway, I convert the GdkColor to RGBA using the macro: GdkColor *color; // read from the hildon_color widget guint alpha = 0xFF; // no transparency guint rgba = GNOME_CANVAS_COLOR_A (color-red, color-green, color-blue, alpha) and then use it wherever it is needed. This works for the predefined colors in the color chooser dialog. But if I choose my own custom color it does not. If I use the GdkColor as is (thus passing fill-color-gdk to the canvas items), it works, but I can't use the alpha channel (can I ?). If I convert this custom color to RGBA with the given macro, it paints in a totally different color. Is this some issue with the colormap ? Is GNOME_CANVAS_COLOR_A not good for this ? Any other hints ? -- anidel -- anidel ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
