mDNSMacOS9/ShowInitIcon.c

   1 // ShowInitIcon - version 1.0.1, May 30th, 1995
   2 // This code is intended to let INIT writers easily display an icon at startup time.
   3 // View in Geneva 9pt, 4-space tabs
   4
   5 // Written by: Peter N Lewis <peter@mail.peter.com.au>, Jim Walker <JWWalker@aol.com>
   6 // and François Pottier <pottier@dmi.ens.fr>, with thanks to previous ShowINIT authors.
   7 // Send comments and bug reports to François Pottier.
   8
   9 // This version features:
  10 // - Short and readable code.
  11 // - Correctly wraps around when more than one row of icons has been displayed.
  12 // - works with System 6
  13 // - Built with Universal Headers & CodeWarrior. Should work with other headers/compilers.
  14
  15 #include <Memory.h>
  16 #include <Resources.h>
  17 #include <Icons.h>
  18 #include <OSUtils.h>
  19 #include "ShowInitIcon.h"
  20
  21 // You should set SystemSixOrLater in your headers to avoid including glue for SysEnvirons.
  22
  23 // ---------------------------------------------------------------------------------------------------------------------
  24 // Set this flag to 1 if you want to compile this file into a stand-alone resource (see note below).
  25 // Set it to 0 if you want to include this source file into your INIT project.
  26
  27 #if 0
  28 #define ShowInitIcon main
  29 #endif
  30
  31 // ---------------------------------------------------------------------------------------------------------------------
  32 // The ShowINIT mechanism works by having each INIT read/write data from these globals.
  33 // The MPW C compiler doesn't accept variables declared at an absolute address, so I use these macros instead.
  34 // Only one macro is defined per variable; there is no need to define a Set and a Get accessor like in <LowMem.h>.
  35
  36 #define LMVCheckSum             (* (unsigned short*) 0x928)
  37 #define LMVCoord                (* (         short*) 0x92A)
  38 #define LMHCoord                (* (         short*) 0x92C)
  39 #define LMHCheckSum             (* (unsigned short*) 0x92E)
  40
  41 // ---------------------------------------------------------------------------------------------------------------------
  42 // Prototypes for the subroutines. The main routine comes first; this is necessary to make THINK C's "Custom Header" option work.
  43
  44 static unsigned short CheckSum (short x);
  45 static void ComputeIconRect (Rect* iconRect, Rect* screenBounds);
  46 static void AdvanceIconPosition (Rect* iconRect);
  47 static void DrawBWIcon (short iconID, Rect *iconRect);
  48
  49 // ---------------------------------------------------------------------------------------------------------------------
  50 // Main routine.
  51
  52 typedef struct {
  53         QDGlobals                       qd;                                                                     // Storage for the QuickDraw globals
  54         long                            qdGlobalsPtr;                                                   // A5 points to this place; it will contain a pointer to qd
  55 } QDStorage;
  56
  57 pascal void ShowInitIcon (short iconFamilyID, Boolean advance)
  58 {
  59         long                            oldA5;                                                          // Original value of register A5
  60         QDStorage                       qds;                                                                    // Fake QD globals
  61         CGrafPort                       colorPort;
  62         GrafPort                        bwPort;
  63         Rect                            destRect;
  64         SysEnvRec               environment;                                                    // Machine configuration.
  65
  66         oldA5 = SetA5((long) &qds.qdGlobalsPtr);                                                // Tell A5 to point to the end of the fake QD Globals
  67         InitGraf(&qds.qd.thePort);                                                              // Initialize the fake QD Globals
  68
  69         SysEnvirons(curSysEnvVers, &environment);                                       // Find out what kind of machine this is
  70
  71         ComputeIconRect(&destRect, &qds.qd.screenBits.bounds);                  // Compute where the icon should be drawn
  72
  73         if (environment.systemVersion >= 0x0700 && environment.hasColorQD) {
  74                 OpenCPort(&colorPort);
  75                 PlotIconID(&destRect, atNone, ttNone, iconFamilyID);
  76                 CloseCPort(&colorPort);
  77         }
  78         else {
  79                 OpenPort(&bwPort);
  80                 DrawBWIcon(iconFamilyID, &destRect);
  81                 ClosePort(&bwPort);
  82         }
  83
  84         if (advance)
  85                 AdvanceIconPosition (&destRect);
  86
  87         SetA5(oldA5);                                                                                   // Restore A5 to its previous value
  88 }
  89
  90 // ---------------------------------------------------------------------------------------------------------------------
  91 // A checksum is used to make sure that the data in there was left by another ShowINIT-aware INIT.
  92
  93 static unsigned short CheckSum (short x)
  94 {
  95         return (unsigned short)(((x << 1) | (x >> 15)) ^ 0x1021);
  96 }
  97
  98 // ---------------------------------------------------------------------------------------------------------------------
  99 // ComputeIconRect computes where the icon should be displayed.
 100
 101 static void ComputeIconRect (Rect* iconRect, Rect* screenBounds)
 102 {
 103         if (CheckSum(LMHCoord) != LMHCheckSum)                                  // If we are first, we need to initialize the shared data.
 104                 LMHCoord = 8;
 105         if (CheckSum(LMVCoord) != LMVCheckSum)
 106                 LMVCoord = (short)(screenBounds->bottom - 40);
 107
 108         if (LMHCoord + 34 > screenBounds->right) {                                      // Check whether we must wrap
 109                 iconRect->left = 8;
 110                 iconRect->top = (short)(LMVCoord - 40);
 111         }
 112         else {
 113                 iconRect->left = LMHCoord;
 114                 iconRect->top = LMVCoord;
 115         }
 116         iconRect->right  = (short)(iconRect->left + 32);
 117         iconRect->bottom = (short)(iconRect->top  + 32);
 118 }
 119
 120 // AdvanceIconPosition updates the shared global variables so that the next extension will draw its icon beside ours.
 121
 122 static void AdvanceIconPosition (Rect* iconRect)
 123 {
 124         LMHCoord = (short)(iconRect->left + 40);                                        // Update the shared data
 125         LMVCoord = iconRect->top;
 126         LMHCheckSum = CheckSum(LMHCoord);
 127         LMVCheckSum = CheckSum(LMVCoord);
 128 }
 129
 130 // DrawBWIcon draws the 'ICN#' member of the icon family. It works under System 6.
 131
 132 static void DrawBWIcon (short iconID, Rect *iconRect)
 133 {
 134         Handle          icon;
 135         BitMap          source, destination;
 136         GrafPtr         port;
 137
 138         icon = Get1Resource('ICN#', iconID);
 139         if (icon != NULL) {
 140                 HLock(icon);
 141                                                                                                                 // Prepare the source and destination bitmaps.
 142                 source.baseAddr = *icon + 128;                                          // Mask address.
 143                 source.rowBytes = 4;
 144                 SetRect(&source.bounds, 0, 0, 32, 32);
 145                 GetPort(&port);
 146                 destination = port->portBits;
 147                                                                                                                 // Transfer the mask.
 148                 CopyBits(&source, &destination, &source.bounds, iconRect, srcBic, nil);
 149                                                                                                                 // Then the icon.
 150                 source.baseAddr = *icon;
 151                 CopyBits(&source, &destination, &source.bounds, iconRect, srcOr, nil);
 152         }
 153 }
 154
 155 // ---------------------------------------------------------------------------------------------------------------------
 156 // Notes
 157
 158 // Checking for PlotIconID:
 159 // We (PNL) now check for system 7 and colour QD, and use colour graf ports and PlotIconID only if both are true
 160 // Otherwise we use B&W grafport and draw using PlotBWIcon.