Copyright Ó 1993 by Xerox Corporation. All rights reserved.

Christian Jacobi, October 22, 1993 5:15 pm PDT

This demonstrates how to create an imager context which paints into foreign X windows..

This is not a useful application in itself, but can be used for demo, or, code stealing.

Commander, CommanderOps, Convert, Imager, ImagerBackdoor, ImagerColor, IO, Rope, Xl, XTk, XTkBitmapWidgets, XTkShellWidgets;

IMPORTS Commander, CommanderOps, Convert, Imager, ImagerBackdoor, ImagerColor, IO, Xl, Rope, XTkBitmapWidgets, XTkShellWidgets =

--"Erases" with a visible pattern (for debugging)

Imager.SetColor[lastContext, Imager.MakeGray[0.1]];

Imager.MaskRectangleI[lastContext, 0, 0, 10000, 10000];

};

--Paint some pattern

Imager.SetColor[lastContext, Imager.black];

Imager.MaskRectangleI[lastContext, 10, 0, 4, 10000];

Imager.SetStrokeWidth[lastContext, 2];

Imager.MaskVectorI[lastContext, 0, 0, 10000, 10000];

Imager.SetStrokeWidth[lastContext, 8];

Imager.MaskVectorI[lastContext, 20, 20, 100, 100];

Imager.SetColor[lastContext, ImagerColor.ColorFromRGB[[1.0, 0.0, 0.0]]]; --use color to expose whether actual context supports colors

Imager.SetStrokeWidth[lastContext, 10];

Imager.MaskVectorI[lastContext, 20, 100, 100, 20];

};

--This procedure represents the application which needs to know when to create new imager contexts.

--For debugging we paint a certain pattern

c: Imager.Context ¬ lastContext ¬ CreateContext[bitmapWidget];

IO.PutF[lastStream, "w: %g, h: %g\n", IO.int[size.width], IO.int[size.height]];

lastWidget ¬ bitmapWidget;

Erase[];

Paint[];

};

size: Xl.Size ~ bitmapWidget.actual.size;

XTkBitmapWidgets.CreateAndSetBitmap[widget: bitmapWidget, size: [s: size.height, f: size.width], bpp: bitsPerPixel];

ApplicationReportNewSize[bitmapWidget, size];

};

--This also allocates a new bitmap on resize so the bitmap tracks the size of the widget

--But that is optional, the bitmap and the widget may differ in size

IF reason=destroyWindow THEN {

IF reason=createWindow OR reason=resize THEN {

};

--Main procedure, creating a window which supports an imager context.

--windowId: window to be used

--server: X server to be used. A rope specifying the name, an Xl.Connection, or, NIL. A defaulted server will fall back to a long list of defaults, ending up with using the display environment variable

foreignParent: Xl.Window ~ [[windowId]];

shellWidget: XTk.Widget ¬ XTkShellWidgets.CreateInteroperabilityShell[]; --creates data structures ready to graft on our stuff

bitmapWidget ¬ XTkBitmapWidgets.CreateBitmapWidget[notify: BitmapEventHappened];

XTkShellWidgets.SetShellChild[shellWidget, bitmapWidget];

XTkShellWidgets.BindScreenShell[shellWidget, server, foreignParent];

XTkShellWidgets.RealizeShell[shellWidget];

};

--This imager context paints into the currently active backing bitmap. It will continue painting int the same old backing bitmap even if the bitmapWidget would display another bitmap.

RETURN [XTkBitmapWidgets.CreateContext[bitmapWidget]];

};

--Main command exercising this package

arg: Rope.ROPE ¬ CommanderOps.NextArgument[cmd];

id: CARD;

SELECT TRUE FROM

id ¬ Convert.CardFromRope[arg ! Convert.Error => CommanderOps.Failed["need id"]];

lastStream ¬ cmd.out;

[] ¬ CreateContextWidget[id, NIL ! Xl.XError => CommanderOps.Failed[err.explanation]];

};

--Explicitely paint the background for debugging

Erase[];

};

--Explicitely paint for debugging

Paint[];

};

--Write the imager bounds for debugging

r: Imager.Rectangle ¬ ImagerBackdoor.GetBounds[lastContext];

IO.PutF[cmd.out, "Bounds x: %g, y:%g, ", IO.real[r.x], IO.real[r.y]];

IO.PutF[cmd.out, "w: %g, h: %g\n", IO.real[r.w], IO.real[r.h]];

};

--Direct X commands for drawing; this can expose whether the window is actually not clipped

w: Xl.Window ¬ lastWidget.window;

c: Xl.Connection ¬ lastWidget.connection;

gc: Xl.GContext ¬ Xl.MakeGContext[c, w];

screen: Xl.Screen ¬ lastWidget.screenDepth.screen;

size: Xl.Size ¬ lastWidget.actual.size;

Xl.SetGCForeground[gc, screen.blackPixel];

Xl.SetGCBackground[gc, screen.whitePixel];

Xl.SetGCFunction[gc, copy];

Xl.SetGCLineWidth[gc, 3];

Xl.DrawLine[c, w, [0, 0], [size.width, size.height], gc];

Xl.Flush[c];

IO.PutF[cmd.out, "Size w: %g, h:%g\n", IO.int[size.width], IO.int[size.height]];

};