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2009-01-29 Tor Lillqvist <tml@novell.com> Bug 559408 - Transparency lost when images are copied between GTK+ and the clipboard on Windows The code in gdkselection-win32.c is simplified quite a lot. When an image is stored on the clipboard from GTK+, only the "PNG" and CF_DIB formats are advertised. PNG is our preferred format because it can losslessly represent any image that gdk-pixbuf can handle, even with alpha, unambiguously. CF_DIB is also advertised because of its ubiquitous support in Windows software. Delayed rendering is used as before, so for other data than text nothing is actually stored on the clipboard until some app asks for it. It's pointless to advertise images formats like "image/png" or "image/x-MS-bmp" that no other Windows application is going to look for anyway. Likewise it's pointless to store text under formats like "text/plain" or "UTF8_STRING". Just store CF_UNICODETEXT. CF_TEXT will be available as a synthesized format anyways. Office 2007 offers and asks for images in PNG format using the registered clipboard format name "PNG", so we do likewise. If the "PNG" format is available that is preferred when copying to GTK+ from the clipboard. Unfortunately Word 2007 still uses CF_DIB without handling alpha. But PowerPoint 2007 uses PNG if available and handles alpha correctly. Both Word and Powerpoint offer PNG with alpha nicely. Firefox and IE7 offer images that contain alpha as 32-bit version 3 BI_RGB DIBs with the undocumented "extra" bytes actually being alpha. Also, alpha is premultiplied into the RGB bytes, presumably because that is how AlphaBlend() wants such DIBs. That is also taken care of. At least for Firefox it easy to be sure that a CF_DIB on the clipboard is from Firefox. Also some general stylistic cleanup, comment improvements, and improvements of debugging printout especially in the clipboard handling. Those are not detailled below. * gdk/win32/gdkprivate-win32.h * gdk/win32/gdkglobals-win32.c * gdk/win32/gdkgmain-win32.c: Move some globals that were used only in gdkselection-win32.c to be local to that file. * gdk/win32/gdkproperty-win32.c (gdk_property_change): Don't bother checking if text to be placed on the clipboard consists of only ASCII. * gdk/win32/gdkselection-win32.c: Add static variables for a list of GdkPixbuf-supported formats, well-known registered clipboard formats for images, and for GdkAtoms for well-known image and text formats. (_gdk_win32_selection_init): Initialize above static variables. (selection_property_store) (gdk_selection_property_get) (_gdk_selection_property_delete): Don't use a FIFO of GdkSelProps for a window after all, it breaks testtext. See bug #163844. (gdk_selection_convert): When converting to the TARGETS format, i.e. when the caller wants to know what clipboard formats are available, if PNG is available we report just that and skip CF_DIB, JPEG and GIF even if advertised. If CF_UNICODETEXT is available, report only UTF8_STRING. When converting to the UTF8_STRING format, i.e. when the caller wants text from the clipboard, try just CF_UNICODETEXT. There is no point in trying CF_TEXT as Windows will synthesize CF_UNICODETEXT from CF_TEXT anyway, if some app has stored just CF_TEXT. When converting to the image/bmp format, i.e. when the caller wants an CF_DIB image from the clipboard, we check if the DIB is a version 3 32-bit BI_RGB one that is likely to actually contain alpha in the "extra" bytes. Such a DIB is likely to have premultiplied alpha even, at least in the case of Firefox 3 and IE7. We then edit the DIB in-place into a version 5 one in BI_BITFIELDS format and undo the alpha premultiplication. In any case, prepend a BMP file header before letting go of the data which will be fed to the gdk-pixbuf bmp loader by upper levels. (gdk_win32_selection_add_targets): If some kind of pixmap image format is being added, actually advertise just PNG and CF_DIB. Note that alpha won't be stored on the clipboard through CF_DIB. This is because gdk-pixbuf's bmp loader doesn't save alpha. Furthermore, few if any non-GTK+ Windows apps seem to understand a version 5 DIB with proper alpha anyway. (_gdk_win32_selection_convert_to_dib): Simplified muchly. svn path=/trunk/; revision=22255 |
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| .. | ||
| rc | ||
| bdfcursor.c | ||
| cursor.bdf | ||
| gdkapplaunchcontext-win32.c | ||
| gdkcolor-win32.c | ||
| gdkcursor-win32.c | ||
| gdkdisplay-win32.c | ||
| gdkdnd-win32.c | ||
| gdkdrawable-win32.c | ||
| gdkdrawable-win32.h | ||
| gdkevents-win32.c | ||
| gdkfont-win32.c | ||
| gdkgc-win32.c | ||
| gdkgeometry-win32.c | ||
| gdkglobals-win32.c | ||
| gdkim-win32.c | ||
| gdkimage-win32.c | ||
| gdkinput-win32.c | ||
| gdkinput-win32.h | ||
| gdkinput.c | ||
| gdkkeys-win32.c | ||
| gdkmain-win32.c | ||
| gdkpixmap-win32.c | ||
| gdkpixmap-win32.h | ||
| gdkprivate-win32.h | ||
| gdkproperty-win32.c | ||
| gdkscreen-win32.c | ||
| gdkselection-win32.c | ||
| gdkspawn-win32.c | ||
| gdktestutils-win32.c | ||
| gdkvisual-win32.c | ||
| gdkwin32.h | ||
| gdkwin32id.c | ||
| gdkwindow-win32.c | ||
| gdkwindow-win32.h | ||
| libwntab32x.la | ||
| Makefile.am | ||
| makefile.msc | ||
| pktdef.h | ||
| wintab.h | ||
| xcursors.h | ||