/***************************************************************************** COLOURDEMO AUTHOR: Renae BATINA FILE: TUTORIALS.DIR/DEMOS.DIR/COLOURDEMO.C INSTITUTION: Curtin University of Technology Bentley, Western Australia TO COMPILE: cc -o colourdemo colourdemo.c -lX11 Must have header file called colourheader.h DESCRIPTION: This program takes a header file which contains colours avaliable on the system in use. It then draws all the colours in a grid. When the mouse button is clicked on one of these colours, the name of the colour will appear and the position of the colour in the header file. ******************************************************************************/ /* * INCLUDE FILES */ #include #include #include #if 1 #include "colourheader.h" /* header file for colour */ #else #include "greyheader.h" /* header file for grey */ #endif /* * CONSTANT DECLARATIONS */ #define FALSE 0 #define TRUE 1 #define INVALID -1 /* invalid position */ #define BORDER 50 /* width of the border */ #define START BORDER*2 /* start position away from the boarder */ #define INCR BORDER /* how big the shaded grid lines are apart */ #define NUMACROSS 12 /* number of colours across the grid */ #define QUITXPOS BORDER /* x position of quit box */ #define QUITYPOS BORDER /* y position of quit box */ #define QUITWIDTH BORDER+BORDER/2 /* width of the quit box */ #define QUITHEIGHT BORDER/2 /* height of quit box */ #define QUITXSTR BORDER + 10 /* x position of quit string */ #define QUITYSTR 70 /* y position of quit string */ #define NUMXPOS 290 /* x position where to write array pos */ #define NUMYPOS 75 /* y position of all information */ #define COLXPOS 340 /* x position of colour name */ /****************************************************************************** WINDOW OPENWINDOW ****************************************************************************** DESCRIPTION: Creates a window with particular attributes and then maps this window onto the screen. In addition to this, open_window also creates a graphics context for the window which allows the window to be drawn to. Xlib ROUTINES USED: XCreateWindow Creates a window given particular attributes. XDestroyWindow Unmaps a window and destroys it. XFlush Flushes the buffer. XMapWindow Draws a window to the screen. XSetStandardProperties Sets the minimum set of properties for the window manager. OTHER ROUTINES USED: createGC Function which return a graphics context for a window. ******************************************************************************/ Window OpenWindow(myDisplay,myScreen,myDepth,x, y, width, height, myGC,myWhitePixel,myBlackPixel) Display *myDisplay; /* pointer to the display */ int myScreen; /* screen we are using */ int myDepth; /* colour plane depth */ int x, y; /* coords of top left corner of window */ unsigned int width, height; /* dimensions of the window */ GC *myGC; /* graphics context for the window */ unsigned long myWhitePixel; /* pixel value for white */ unsigned long myBlackPixel; /* pixel value for black */ { int border_width = 20; /* border width of the window */ char *HEADING = "XColours"; XSetWindowAttributes myWindowAttributes; /* structure of window attibutes */ unsigned long myWindowMask; /* mask for window attributes */ XSizeHints theSizeHints; /* window hints for window manger */ static Window myWindow; /* window structure */ /* * SET WINDOW ATTRIBUTES */ /* border colour */ myWindowAttributes.border_pixel = BlackPixel (myDisplay, myScreen); /* background colour */ myWindowAttributes.background_pixel = WhitePixel (myDisplay, myScreen); /* if window manager intervene or not */ myWindowAttributes.override_redirect = True; /* create mask for attributes */ myWindowMask = CWBackPixel | CWBorderPixel | CWOverrideRedirect; /* * CREATE THE WINDOW */ myWindow = XCreateWindow (myDisplay, RootWindow (myDisplay, myScreen), x, y, width, height, border_width, myDepth, InputOutput, CopyFromParent, myWindowMask, &myWindowAttributes); /* * SETUP HINTS FOR WINDOW MANAGER */ theSizeHints.flags = PPosition | PSize; /* set mask for the hints */ theSizeHints.x = x; /* x position */ theSizeHints.y = y; /* y position */ theSizeHints.width = width; /* width of the window */ theSizeHints.height = height; /* height of the window */ /* * PASS HINTS TO WINDOW MANAGER */ XSetStandardProperties (myDisplay, myWindow, HEADING, HEADING, None, NULL, 0, &theSizeHints); /* * SET GRAPHICS CONTEXT FOR THE WINDOW */ if (CreateGC (myDisplay,myWindow, myGC,myWhitePixel,myBlackPixel) == 0) { XDestroyWindow(myDisplay, myScreen); return ((Window)0); } /* * MAP WINDOW ONTO THE SCREEN */ XMapWindow (myDisplay, myWindow); XFlush (myDisplay); return(myWindow); } /***************************************************************************** INT CREATEGC **************************************************************************** DESCRIPTION: Creates a graphics context for a given window. It sets the forground colour to black and the background colour to white. If a GC cannot be created, then 0 is returned to the calling routine, otherwise 1 is returned as well as the GC. Xlib ROUTINES USED: XCreateGC Create a new graphics context for a given display with the depth of the specified window. XSetForeground Sets the forground colour in a graphics context. XSetBackground Sets the background colour in a graphics context. OTHER ROUTINES USED: None *****************************************************************************/ int CreateGC (myDisplay,myWindow, myGC,myBlackPixel,myWhitePixel) /* This function creates a given graphic context for a given window */ Display *myDisplay; /* pointer to the display */ Window myWindow; GC *myGC; unsigned long myWhitePixel; /* pixel value for white */ unsigned long myBlackPixel; /* pixel value for black */ { XGCValues myGCValues; /* * CREATE THE GRAPHICS CONTEXT */ *myGC = XCreateGC (myDisplay, myWindow, (unsigned long) 0, &myGCValues); /* * CHECK IF CREATED OK */ if (*myGC == 0) return (0); else /* set forground and background defaults */ { XSetForeground (myDisplay, *myGC, myBlackPixel); XSetBackground (myDisplay, *myGC, myWhitePixel); return (1); } } /***************************************************************************** VOID RECTANGLE ****************************************************************************** DESCRIPTION: Draws a rectangle with its top left corner at position x, y and has dimensions of width and height. To draw a box, width and height are the same. Xlib ROUTINES USED: XDrawRectangle Draws an outline of a rectangle. ******************************************************************************/ void Rectangle (myDisplay,myWindow, myGC, x, y, width, height) Display *myDisplay; /* pointer to the display */ Window myWindow; /* drawable window */ GC myGC; /* graphics context for the window */ int x, y; /* top left corner of the rectangle */ unsigned int width, height; /* dimensions of the rectangle */ { XDrawRectangle (myDisplay, myWindow, myGC, x, y, width, height); } /***************************************************************************** VOID FILLRECTANGLE ***************************************************************************** DESCRIPTION: Draws a filled rectangle with its top left corner at postion x, y and with dimensions of width and height. Xlib ROUTINES USED: XFillRectangle Draws a filled rectangle. *****************************************************************************/ void FillRectangle (myDisplay,myWindow, myGC, x, y, width, height) Display *myDisplay; /* pointer to the display */ Window myWindow; /* drawable window */ GC myGC; /* graphics context for the window */ int x, y; /* top left corner of the rectangle */ unsigned int width, height; /* dimensions of the rectangle */ { XFillRectangle (myDisplay, myWindow, myGC, x, y, width, height); } /****************************************************************************** VOID INIT **************************************************************************** DESCRIPTION: First of all, this procedure establishes a connection between the client and the X server. It then finds out information about the display that the program is running on. For example, it determines if the screen is colour or monochrome. Xlib ROUTINES USED: BlackPixel Returns the black pixel value in the default colour map DefaultColormap Returns the default colour map for the specified screen. DefaultScreen Returns the integer specified by XOpenDisplay. WhitePixel Returns the white pixel value in the default colour map XDisplayName Reports the display name. XOpenDisplay Connects a client program with the server. *******************************************************************************/ void init(myDisplay,myScreen,myDepth,myColourmap,myWhitePixel,myBlackPixel) Display **myDisplay; /* pointer to the display */ int *myScreen; /* screen we are using */ int *myDepth; /* colour plane depth */ Colormap *myColourmap; /* systems default colour map */ unsigned long *myWhitePixel; /* pixel value for white */ unsigned long *myBlackPixel; /* pixel value for black */ { /* * MAKE CONNECTION WITH THE SERVER */ *myDisplay = XOpenDisplay (""); if (*myDisplay == NULL) { fprintf (stderr, "ERROR: Could not open a connection to X on display %s\n", XDisplayName (NULL)); exit (0); } /* * INFORMATION ABOUT THE SCREEN */ *myScreen = DefaultScreen (*myDisplay); /* * FINDING THE NUMBER OF COLOUR PLANES AND GET THE DEFAULT COLOUR MAP */ *myDepth = DefaultDepth (*myDisplay, *myScreen); *myColourmap = DefaultColormap (*myDisplay, *myScreen); /* * GET INFO FOR THE GRAPHICS CONTEXT */ *myWhitePixel = WhitePixel (*myDisplay, *myScreen); *myBlackPixel = BlackPixel (*myDisplay, *myScreen); } /****************************************************************************** FONTSTRUCT *INITFONT **************************************************************************** DESCRIPTION: Obtains information about a certian font and then stores this information into a font structure for later use. Xlib ROUTINES USED: XLoadQueryFont Load a font and fill the font structure. XSetFont Set the font into the given graphics context. ******************************************************************************/ XFontStruct * InitFont (myDisplay,myGC, fontName) Display *myDisplay; /* pointer to the display */ GC myGC; /* gc in which to set the font */ char fontName[]; /* name of the font to set */ { XFontStruct *fontstruct; /* structure to fill with font info */ /* * LOAD FONT */ fontstruct = XLoadQueryFont (myDisplay, fontName); /* * IF FONT OK, LOAD INFO INTO THE FONT STRUCTURE */ if (fontstruct != 0) XSetFont (myDisplay, myGC, fontstruct->fid); /* * RETURN THE FONT STUCTURE */ return(fontstruct); } /***************************************************************************** VOID INITCOLOURS ***************************************************************************** DESCRIPTION: Initializes a series of colours and finds the hardware pixel value for them. This value is stored in an array which can be accessed at anytime. This saves the program time as it does not need to continually look up the same colour. Xlib ROUTINES USED: XAllocColor Allocate a read only colourmap cell with the closest hardware supported colour. XLookupColor Get database RGB values and closest hardware supported RGB values from the colour name specified. *****************************************************************************/ void InitColours(myDisplay, myColourmap,myDepth,colourpixels,myWhitePixel,myBlackPixel) Display *myDisplay; /* pointer to the display */ Colormap myColourmap; /* systems default colour map */ int myDepth; /* colour plane depth */ unsigned long colourpixels[NUMCOLOURS];/* stores pixel values */ unsigned long myWhitePixel; /* pixel value for white */ unsigned long myBlackPixel; /* pixel value for black */ { int col,loop; /* loop counter */ XColor hwarecolour; /* closest rgb colour for the hardware */ int status; /* determines if function ok */ /* * COLOUR SCREEN */ if (myDepth > 1) { for (col=0,loop=0; loop= 0) && (number < NUMCOLOURS)) /* set the drawing colour */ XSetForeground (myDisplay, myGC, colourpixels[number]); } /***************************************************************************** VOID CALCULATEWHERE **************************************************************************** DESCRIPTION: Calculates the square which is the closest to where the mouse click was made. ******************************************************************************/ void CalculateWhere (oldx, oldy, newx, newy ) int oldx, oldy; /* position at where mouse is */ int *newx, *newy; /* position of closest top corner */ { int tmp; /* temporary variables */ /* * CALCULATE CLOSEST X COORDINATE */ tmp = BORDER; while (tmp <= oldx) { tmp += INCR; } *newx = tmp - INCR; /* * CALCULATE CLOSEST Y COORDINATE */ tmp = BORDER; while (tmp <= oldy) { tmp += INCR; } *newy = tmp - INCR; } /**************************************************************************** INT CALCULATECOLOUR **************************************************************************** DESCRIPTION: Determines what colour square the mouse click was made on. ****************************************************************************/ int CalculateColour(x, y) int x, y; { int tmpx, tmpy, pos; /* * DONT INCLUDE THE BORDER */ tmpx = x - BORDER; tmpy = y - START; /* * CALCULATE NUMBER OF INCREMENTS IN FOR X */ if (tmpx != 0) x = tmpx/INCR; else x = 0; /* * CALCULATE NUMBER OF INCREMENTS IN FOR Y */ if (tmpy != 0) y = tmpy/INCR; else y = 0; /* DETERMINE POSITION IN ARRAY */ pos = NUMACROSS*y + x; /* * DETERMINE IF VALID */ if (pos >= NUMCOLOURS) pos = INVALID; return (pos); } /****************************************************************************** VOID WRITECOLOURDETAILS ***************************************************************************** DESCRIPTION: Writes to the screen the name of the colour which has been selected from the colour chart. It also writes the position in the array the colour is located at. Xlib ROUTINES USED: XDrawImageString Draws an 8-bit image text characters. OTHER ROUTINES USED: InitFont Initializes the font with which to display the text. SetColour Sets the current drawing colour. ******************************************************************************/ void WriteColourDetails (myDisplay, myWindow,myGC,pos) Display *myDisplay; /* connection to X server */ Window myWindow; /* window ID */ GC myGC; /* the graphics context */ int pos; /* position in the array of colours */ { XFontStruct *initfont(); /* function to get the font details */ char *font = "zapfchancery-mediumitalic.24"; char *blanks = " "; char *invalid = "Invalid Choice"; char ch[3]; /* * SET THE DRAWING COLOUR AND THE FONT TYPE */ (void)InitFont (myDisplay,myGC, font); /* * BLANK OUT THE PREVIOUS COLOUR */ XDrawImageString (myDisplay, myWindow, myGC, NUMXPOS-2, NUMYPOS, blanks, strlen(blanks)); /* * IF A VALID POSITION, WRITE THE NAME AND POSITION OF THE COLOUR */ if (pos != INVALID) { /* convert the integer position to a character */ sprintf (ch, "%d", pos); XDrawImageString (myDisplay, myWindow, myGC, NUMXPOS, NUMYPOS, ch, strlen(ch)); XDrawImageString (myDisplay, myWindow, myGC, COLXPOS, NUMYPOS, greynames[pos], strlen(greynames[pos])); } /* * ELSE, INFORM USER THAT AN INVALID CHOICE WAS MADE */ else XDrawImageString (myDisplay, myWindow, myGC, COLXPOS, NUMYPOS, invalid, strlen(invalid)); } /***************************************************************************** VOID DRAWDISPLAY ***************************************************************************** DESCRIPTION: Draws the colour chart in the window with the appropriate title and heading. Xlib ROUTINES USED: XDrawImageString Draws an 8-bit image text string. XFlush Flush the contents of the buffer. OTHER ROUTINES USED: FillRectangle Draws a filled rectangle with the current colour set. InitFont Sets the font to write with. Rectangle Draws the outline of a rectangle. SetColour Sets the drawing colour. ******************************************************************************/ void DrawDisplay (myDisplay,myWindow, myGC,myWhitePixel,myBlackPixel,colourpixels) Display *myDisplay; /* connection to X server */ Window myWindow; GC myGC; unsigned long myWhitePixel; /* pixel value for white */ unsigned long myBlackPixel; /* pixel value for black */ unsigned long colourpixels[NUMCOLOURS];/* stores pixel values */ { int loop, count; /* loop counter */ int ypost; /* y position in the grid */ char *headingfont = "times-bold.32"; /* font for the heading */ char *heading = "X COLOURS"; /* heading of the window */ char *quitfont = "times-bold.17"; /* font for the quit box */ char *quit = "Quit"; /* inside quit box */ /* INITIALIZE VARIABLES */ ypost = START; count = 0; /* * LOOP TO DRAW ALL THE COLOURS */ for (loop=0; loop= QUITXPOS) && (xpos <= QUITWIDTH+QUITXPOS) && (ypos >= QUITYPOS) && (ypos <= QUITHEIGHT+QUITYPOS) ) return (TRUE); /* inside the box */ else return (FALSE); /* not inside the box */ } /*************************************************************************** INT INGRID **************************************************************************** DESCRIPTION: Determines if the mouse button was clicked inside the colour grid or in the white space surrounding the colour grid. ***************************************************************************/ int InGrid (width,height,xpos, ypos) int xpos, ypos; /* position the mouse button was clicked on */ unsigned int width, height; /* dimensions of the window */ { if ( (xpos >= BORDER) && (xpos < width-BORDER) && (ypos >= START ) && (ypos < height-BORDER) ) return (TRUE); /* inside grid */ else return (FALSE); /* in white space */ } /**************************************************************************** VOID POLLEVENTS **************************************************************************** DESCRIPTION: This procedure loops around until the user indicates to stop. On each pass of the loop, if an event has occured, then the correct action for that event will be carried out. The user finishes the program by placing the mouse pointer over the 'Quit' rectangle and presses any of the mouse buttons. The events that the procedure recognises is any movement of the mouse pointer and any button press of the mouse. If the mouse is moved and motion is detected, then it is determined if the mouse is over the 'Quit' box. If it is, then the quit text enlargens to indicate that it has detected where the mouse is. If it is not inside this box, the text is returned to normal size. If a mouse button is pressed, then once again, the program determines if it was inside the 'Quit' box. If it is, then this indicates that the user wishes to finish. However, if it isn't and it is inside the colour grid, then the colour of the square the pointer is in is determined and the colour and position written to the screen. If the pointer is in 'white' space, then an error message of 'Invalid Choice' is given. Xlib ROUTINES USED: XDrawImageString Draws an 8-bit image text character. XNextEvent Gets the next event of any type or window. XSelectInput Sets up the input types to be sent to a window OTHER ROUTINES USED: CalculateColour Determines the positon number in the array the colour selected is. CalculateWhere Determines the position of the mouse pointer in relation to the grid of colours. InitFont Initializes the font to use. InGrid Determines if the position selected by the mouse button is a valid position in the grid. InQuitBox Function which determines if mouse pointer in the quit box or not. WriteColourDetails Writes to the screen in the correct position the name of the colour selected and the postion number it is in the array. *****************************************************************************/ void PollEvents (myDisplay,myWindow, myGC,width,height) unsigned int width, height; /* dimensions of the window */ Display *myDisplay; /* connection to X server */ Window myWindow; GC myGC; { int finished; /* if user wishes to quit */ XEvent myEvent; /* event which has occured */ int newx, newy; /* position of mouse pointer */ int pos; /* font information */ char *bigquitfont = "times-bold.18"; char *smallquitfont = "times-bold.17"; /* * SELECT WHICH EVENTS YOU WANT TO WATCH */ XSelectInput (myDisplay, myWindow, ButtonPressMask | KeyPressMask | PointerMotionMask); finished = FALSE; /* initialize loop control */ /* * START POLLING FOR EVENTS */ while (!finished) { /* read next event in the queue */ XNextEvent (myDisplay, &myEvent); switch (myEvent.type) { /* mouse was moved */ case MotionNotify : CalculateWhere (myEvent.xmotion.x, myEvent.xmotion.y, &newx, &newy); if (InQuitBox(newx, newy)) /* inside quitbox*/ { (void) InitFont (myDisplay,myGC, bigquitfont); XDrawImageString (myDisplay, myWindow, myGC, QUITXSTR, QUITYSTR, "Quit", strlen("Quit")); } else /* not inside quitbox*/ { (void) InitFont (myDisplay,myGC, smallquitfont); XDrawImageString (myDisplay, myWindow, myGC, QUITXSTR, QUITYSTR, "Quit", strlen("Quit")); } break; /* mouse button was pressed */ case ButtonPress: CalculateWhere (myEvent.xbutton.x, myEvent.xbutton.y, &newx, &newy); /* user wishes to finish program */ if (InQuitBox(newx, newy)) finished = TRUE; /* determine if valid position on the grid */ else if (InGrid(width,height,newx, newy)) { pos = CalculateColour(newx, newy); WriteColourDetails (myDisplay, myWindow,myGC,pos); } else /* in white space */ { pos = INVALID; WriteColourDetails (myDisplay, myWindow,myGC,pos); } break; } } } /***************************************************************************** MAINLINE ******************************************************************************/ main (argc, argv) int argc; char **argv; { /* * DECLARATIIONS */ int x = 250; /* x top left corner of window */ int y = 25; /* y top left corner of window */ unsigned int width, height; /* dimensions of the box */ Display *myDisplay; /* pointer to the display */ int myScreen; /* screen we are using */ int myDepth; /* colour plane depth */ Window myWindow; /* Window to display */ Colormap myColourmap; /* systems default colour map */ GC myGC; unsigned long myWhitePixel; /* pixel value for white */ unsigned long myBlackPixel; /* pixel value for black */ unsigned long colourpixels[NUMCOLOURS];/* stores pixel values */ /* * SET THE DIMENSIONS OF THE BOX */ width = NUMACROSS*INCR+START; height = NUMCOLOURS/NUMACROSS*INCR+2*START; /* * INITIALIZE VARIABLES */ init(&myDisplay,&myScreen,&myDepth,&myColourmap,&myWhitePixel,&myBlackPixel); InitColours(myDisplay,myColourmap,myDepth,colourpixels,myWhitePixel,myBlackPixel); /* * OPEN UP A WINDOW */ myWindow = OpenWindow(myDisplay,myScreen,myDepth,x, y, width, height, &myGC,myWhitePixel,myBlackPixel); /* * DO SOME DRAWING IN COLOUR */ DrawDisplay (myDisplay,myWindow, myGC,myWhitePixel,myBlackPixel,colourpixels); /* * POLL FOR EVENTS */ PollEvents (myDisplay,myWindow, myGC,width,height); /* * DRAW VIA FLUSHING THE BUFFERS */ XFlush (myDisplay); /* * DESTROY ALL WINDOWS */ XDestroyWindow (myDisplay, myWindow); XCloseDisplay (myDisplay); /* * EXIT */ exit (0); } /***************************************************************************** END OF FILE COLOURDEMO.C *****************************************************************************/