1mX Nonrectangular Window0m 1mShape Extension Library0m Version 1.0 X Consortium Standard X Version 11, Release 6.4 Keith Packard MIT X Consortium Copyright © 1989 X Consortium Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documenta- tion files (the ``Software''), to deal in the Software with- out restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the fol- lowing conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PUR- POSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABIL- ITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Except as contained in this notice, the name of the X Con- sortium shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the X Consortium. 1m1. Overview0m This extension provides arbitrary window and border shapes within the X11 protocol. The restriction of rectangular windows within the X protocol is a significant limitation in the implementation of many styles of user interface. For example, many transient win- dows would like to display a ``drop shadow'' to give the illusion of 3 dimensions. As another example, some user interface style guides call for buttons with rounded cor- ners; the full simulation of a nonrectangular shape, partic- ularly with respect to event distribution and cursor shape, is not possible within the core X protocol. As a final example, round clocks and nonrectangular icons are desirable visual addition to the desktop. This extension provides mechanisms for changing the visible shape of a window to an arbitrary, possibly disjoint, non- rectangular form. The intent of the extension is to supple- ment the existing semantics, not replace them. In particu- lar, it is desirable for clients that are unaware of the extension to still be able to cope reasonably with shaped windows. For example, window managers should still be able to negotiate screen real estate in rectangular pieces. Toward this end, any shape specified for a window is clipped by the bounding rectangle for the window as specified by the window's geometry in the core protocol. An expected conven- tion would be that client programs expand their shape to fill the area offered by the window manager. 1m2. Description0m Each window (even with no shapes specified) is defined by two regions: the 4mbounding24m 4mregion24m and the 4mclip24m 4mregion24m. The bounding region is the area of the parent window that the window will occupy (including border). The clip region is the subset of the bounding region that is available for sub- windows and graphics. The area between the bounding region and the clip region is defined to be the border of the win- dow. A nonshaped window will have a bounding region that is a rectangle spanning the window, including its border; the clip region will be a rectangle filling the inside dimen- sions (not including the border). In this document, these areas are referred to as the 4mdefault24m 4mbounding24m 4mregion24m and the 4mdefault24m 4mclip24m 4mregion24m. For a window with inside size of 4mwidth0m by 4mheight24m and border width 4mbwidth24m, the default bounding and clip regions are the rectangles (relative to the window ori- gin): 1m10m X Nonrectangular Window Shape Extension Library __ | bounding.x = -4mbwidth0m bounding.y = -4mbwidth0m bounding.width = 4mwidth24m + 2 * 4mbwidth0m bounding.height = 4mheight24m + 2 * 4mbwidth0m clip.x = 0 clip.y = 0 clip.width = 4mwidth0m clip.height = 4mheight0m |__ This extension allows a client to modify either or both of the bounding or clip regions by specifying new regions that combine with the default regions. These new regions are called the 4mclient24m 4mbounding24m 4mregion24m and the 4mclient24m 4mclip0m 4mregion24m. They are specified relative to the origin of the window and are always defined by offsets relative to the window origin (that is, region adjustments are not required when the window is moved). Three mechanisms for specifying regions are provided: a list of rectangles, a bitmap, and an existing bounding or clip region from a window. This is modeled on the specification of regions in graphics contexts in the core protocol and allows a variety of different uses of the extension. When using an existing window shape as an operand in speci- fying a new shape, the client region is used, unless none has been set, in which case the default region is used instead. The 4meffective24m 4mbounding24m 4mregion24m of a window is defined to be the intersection of the client bounding region with the default bounding region. Any portion of the client bounding region that is not included in the default bounding region will not be included in the effective bounding region on the screen. This means that window managers (or other geometry managers) used to dealing with rectangular client windows will be able to constrain the client to a rectangular area of the screen. Construction of the effective bounding region is dynamic; the client bounding region is not mutated to obtain the effective bounding region. If a client bounding region is specified that extends beyond the current default bounding region, and the window is later enlarged, the effective bounding region will be enlarged to include more of the client bounding region. The 4meffective24m 4mclip24m 4mregion24m of a window is defined to be the intersection of the client clip region with both the default clip region and the client bounding region. Any portion of the client clip region that is not included in both the 1m20m X Nonrectangular Window Shape Extension Library default clip region and the client bounding region will not be included in the effective clip region on the screen. Construction of the effective clip region is dynamic; the client clip region is not mutated to obtain the effective clip region. If a client clip region is specified that extends beyond the current default clip region and the win- dow or its bounding region is later enlarged, the effective clip region will be enlarged to include more of the client clip region if it is included in the effective bounding region. The border of a window is defined to be the difference between the effective bounding region and the effective clip region. If this region is empty, no border is displayed. If this region is nonempty, the border is filled using the border-tile or border-pixel of the window as specified in the core protocol. Note that a window with a nonzero border width will never be able to draw beyond the default clip region of the window. Also note that a zero border width does not prevent a window from having a border, since the clip shape can still be made smaller than the bounding shape. All output to the window and visible regions of any subwin- dows will be clipped to the effective clip region. The server must not retain window contents beyond the effective bounding region with backing store. The window's origin (for graphics operations, background tiling, and subwindow placement) is not affected by the existence of a bounding region or clip region. Areas that are inside the default bounding region but out- side the effective bounding region are not part of the win- dow; these areas of the screen will be occupied by other windows. Input events that occur within the default bound- ing region but outside the effective bounding region will be delivered as if the window was not occluding the event posi- tion. Events that occur in a nonrectangular border of a window will be delivered to that window, just as for events that occur in a normal rectangular border. An 4mInputOnly24m window can have its bounding region set, but it is a 4mMatch24m error to attempt to set a clip region on an 4mInpu-0m 4mtOnly24m window or to specify its clip region as a source to a request in this extension. The server must accept changes to the clip region of a root window, but the server is permitted to ignore requested changes to the bounding region of a root window. If the server accepts bounding region changes, the contents of the screen outside the bounding region are implementation depen- dent. 1m30m X Nonrectangular Window Shape Extension Library 1m3. C Language Binding0m The C functions provide direct access to the protocol and add no additional semantics. The include file for this extension is <4mX11/exten-0m 4msions/shape.h24m>. The defined shape kinds are 4mShapeBounding0m and 4mShapeClip24m. The defined region operations are 4mShapeSet24m, 4mShapeUnion24m, 4mShapeIntersect24m, 4mShapeSubtract24m, and 4mShapeInvert24m. __ | Bool XShapeQueryExtension(4mdisplay24m, 4mevent_base24m, 4merror_base24m) Display *4mdisplay24m; int *4mevent_base24m; /* RETURN */ int *4merror_base24m; /* RETURN */ |__ 4mXShapeQueryExtension24m returns 4mTrue24m if the specified display supports the SHAPE extension else 4mFalse24m. If the extension is supported, *event_base is set to the event number for 4mShapeNotify24m events and *error_base would be set to the error number for the first error for this extension. Because no errors are defined for this version of the extension, the value returned here is not defined (nor useful). __ | Status XShapeQueryVersion(4mdisplay24m, 4mmajor_version24m, 4mminor_version24m) Display *4mdisplay24m; int *4mmajor_version24m, *4mminor_version24m; /* RETURN */ |__ If the extension is supported, 4mXShapeQueryVersion24m sets the major and minor version numbers of the extension supported by the display and returns a nonzero value. Otherwise, the arguments are not set and zero is returned. __ | XShapeCombineRegion(4mdisplay24m, 4mdest24m, 4mdest_kind24m, 4mx_off24m, 4my_off24m, 4mregion24m, 4mop24m) Display *4mdisplay24m; Window 4mdest24m; int 4mdest_kind24m, 4mop24m, 4mx_off24m, 4my_off24m; REGION *4mregion24m; |__ 4mXShapeCombineRegion24m converts the specified region into a 1m40m X Nonrectangular Window Shape Extension Library list of rectangles and calls 4mXShapeCombineRectangles24m. __ | XShapeCombineRectangles(4mdisplay24m, 4mdest24m, 4mdest_kind24m, 4mx_off24m, 4my_off24m, 4mrectangles24m, 4mn_rects24m, 4mop24m, 4mordering24m) Display *4mdisplay24m; Window 4mdest24m; int 4mdest_kind24m, 4mn_rects24m, 4mop24m, 4mx_off24m, 4my_off24m, 4mordering24m; XRectangle *4mrectangles24m; |__ If the extension is supported, 4mXShapeCombineRectangles24m per- forms a 4mShapeRectangles24m operation; otherwise, the request is ignored. __ | XShapeCombineMask(4mdisplay24m, 4mdest24m, 4mdest_kind24m, 4mx_off24m, 4my_off24m, 4msrc24m, 4mop24m) Display *4mdisplay24m; Window 4mdest24m; int 4mdest_kind24m, 4mop24m, 4mx_off24m, 4my_off24m; Pixmap 4msrc24m; |__ If the extension is supported, 4mXShapeCombineMask24m performs a 4mShapeMask24m operation; otherwise, the request is ignored. __ | XShapeCombineShape(4mdisplay24m, 4mdest24m, 4mdest_kind24m, 4mx_off24m, 4my_off24m, 4msrc24m, 4msrc_kind24m, 4mop24m) Display *4mdisplay24m; Window 4mdest24m, 4msrc24m; int 4mdest_kind24m, 4msrc_kind24m, 4mop24m, 4mx_off24m, 4my_off24m; |__ If the extension is supported, 4mXShapeCombineShape24m performs a 4mShapeCombine24m operation; otherwise, the request is ignored. 1m50m X Nonrectangular Window Shape Extension Library __ | XShapeOffsetShape(4mdisplay24m, 4mdest24m, 4mdest_kind24m, 4mx_off24m, 4my_off24m) Display *4mdisplay24m; Window 4mdest24m; int 4mdest_kind24m, fIx_off4m,24m 4my_off;0m |__ If the extension is supported, 4mXShapeOffsetShape24m performs a 4mShapeOffset24m operation; otherwise, the request is ignored. __ | Status XShapeQueryExtents(4mdisplay24m, 4mwindow24m, 4mbounding_shaped24m, 4mx_bounding24m, 4my_bounding24m, 4mw_bounding24m, 4mh_bounding24m, 4mclip_shaped24m, 4mx_clip24m, 4my_clip24m, 4mw_clip24m, 4mh_clip24m) Display *4mdisplay24m; Window 4mwindow24m; Bool *4mbounding_shaped24m, *4mclip_shaped24m; /* RETURN */ int *4mx_bounding24m, *4my_bounding24m, *4mx_clip24m, *4my_clip24m; /* RETURN */ unsigned int *4mw_bounding24m, *4mh_bounding24m, *4mw_clip24m, * 4mh_clip24m; /* RETURN */ |__ If the extension is supported, 4mXShapeQueryExtents24m sets x_bounding, y_bounding, w_bounding, h_bounding to the extents of the bounding shape and sets x_clip, y_clip, w_clip, h_clip to the extents of the clip shape. For unspecified client regions, the extents of the corresponding default region are used. If the extension is supported, a nonzero value is returned; otherwise, zero is returned. __ | XShapeSelectInput(4mdisplay24m, 4mwindow24m, 4mmask24m) Display *4mdisplay24m; Window 4mwindow24m; unsigned long 4mmask24m; |__ To make this extension more compatible with other inter- faces, although only one event type can be selected via the extension, 4mXShapeSelectInput24m provides a general mechanism similar to the standard Xlib binding for window events. A mask value has been defined, 4mShapeNotifyMask24m that is the only valid bit in mask that may be specified. The structure for this event is defined as follows: 1m60m X Nonrectangular Window Shape Extension Library __ | typedef struct { int type; /* of event */ unsigned long serial;/* # of last request processed by server */ Bool send_event;/* true if this came frome a SendEvent request */ Display *display;/* Display the event was read from */ Window window;/* window of event */ int kind; /* ShapeBounding or ShapeClip */ int x, y; /* extents of new region */ unsigned width, height; Time time; /* server timestamp when region changed */ Bool shaped;/* true if the region exists */ } XShapeEvent; |__ __ | unsigned long XShapeInputSelected(4mdisplay24m, 4mwindow24m) Display *4mdisplay24m; Window 4mwindow24m; |__ 4mXShapeInputSelected24m returns the current input mask for extension events on the specified window; the value returned if 4mShapeNotify24m is selected for is 4mShapeNotifyMask24m; other- wise, it returns zero. If the extension is not supported, it returns zero. __ | XRectangle * XShapeGetRectangles(4mdisplay24m, 4mwindow24m, 4mkind24m, 4mcount24m, 4mordering24m) Display *4mdisplay24m; Window 4mwindow24m; int 4mkind24m; int *4mcount24m; /* RETURN */ int *4mordering24m; /* RETURN */ |__ If the extension is not supported, 4mXShapeGetRectangles0m returns NULL. Otherwise, it returns a list of rectangles that describe the region specified by kind. 1m4. Glossary0m 1m70m X Nonrectangular Window Shape Extension Library 1mbounding region0m The area of the parent window that this window will occupy. This area is divided into two parts: the bor- der and the interior. 1mclip region0m The interior of the window, as a subset of the bounding region. This region describes the area that will be painted with the window background when the window is cleared, will contain all graphics output to the win- dow, and will clip any subwindows. 1mdefault bounding region0m The rectangular area, as described by the core protocol window size, that covers the interior of the window and its border. 1mdefault clip region0m The rectangular area, as described by the core protocol window size, that covers the interior of the window and excludes the border. 1mclient bounding region0m The region associated with a window that is directly modified via this extension when specified by 4mShape-0m 4mBounding24m. This region is used in conjunction with the default bounding region to produce the effective bound- ing region. 1mclient clip region0m The region associated with a window that is directly modified via this extension when specified by 4mShapeClip24m. This region is used in conjunction with the default clip region and the client bounding region to produce the effective clip region. 1meffective bounding region0m The actual shape of the window on the screen, including border and interior (but excluding the effects of over- lapping windows). When a window has a client bounding region, the effective bounding region is the intersec- tion of the default bounding region and the client bounding region. Otherwise, the effective bounding region is the same as the default bounding region. 1m80m X Nonrectangular Window Shape Extension Library 1meffective clip region0m The actual shape of the interior of the window on the screen (excluding the effects of overlapping windows). When a window has a client clip region or a client bounding region, the effective clip region is the intersection of the default clip region, the client clip region (if any) and the client bounding region (if any). Otherwise, the effective clip region is the same as the default clip region. 1m90m