WINGs/mywidget.c

   1 /*
   2  * Demo user widget for WINGs
   3  *
   4  * Author: Alfredo K. Kojima
   5  *
   6  * This file is in the public domain.
   7  *
   8  */
   9
  10
  11 /*
  12  *
  13  * Include the WINGs private data header.
  14  *
  15  *
  16  */
  17 #include "WINGsP.h"
  18
  19 /*
  20  * Our public header.
  21  */
  22 #include "mywidget.h"
  23
  24 /*
  25  * Define the widget "class"
  26  */
  27 typedef struct W_MyWidget {
  28     /* these two fields must be present in all your widgets in this
  29      * exact position */
  30     W_Class widgetClass;
  31     WMView *view;
  32
  33     /* put your stuff here */
  34     char *text;
  35
  36 } _MyWidget;
  37
  38
  39
  40
  41 /* some forward declarations */
  42
  43 static void destroyMyWidget(_MyWidget *mPtr);
  44 static void paintMyWidget(_MyWidget *mPtr);
  45
  46
  47 static void handleEvents(XEvent *event, void *data);
  48 static void handleActionEvents(XEvent *event, void *data);
  49
  50
  51
  52 /*
  53  * Some procedures you might want to override. Don't forget to call
  54  * the equivalent view procedure after (or before) doing your stuff.
  55  * See the source for the other widgets to see how to use.
  56  * You won't need to use this most of the time.
  57  */
  58 static W_ViewProcedureTable _MyWidgetViewProcedures = {
  59         NULL,
  60         NULL,
  61         NULL
  62 };
  63
  64
  65 /* our widget class ID */
  66 static W_Class myWidgetClass = 0;
  67
  68
  69 /*
  70  * Initializer for our widget. Must be called before creating any
  71  * instances of the widget.
  72  */
  73 W_Class
  74 InitMyWidget(WMScreen *scr)
  75 {
  76     /* register our widget with WINGs and get our widget class ID */
  77     if (!myWidgetClass) {
  78         myWidgetClass = W_RegisterUserWidget(&_MyWidgetViewProcedures);
  79     }
  80
  81     return myWidgetClass;
  82 }
  83
  84
  85 /*
  86  * Our widget fabrication plant.
  87  */
  88 MyWidget*
  89 CreateMyWidget(WMWidget *parent)
  90 {
  91     MyWidget *mPtr;
  92
  93     /* allocate some storage for our new widget instance */
  94     mPtr = wmalloc(sizeof(MyWidget));
  95     /* initialize it */
  96     memset(mPtr, 0, sizeof(MyWidget));
  97
  98     /* set the class ID */
  99     mPtr->widgetClass = myWidgetClass;
 100
 101     /*
 102      * Create the view for our widget.
 103      * Note: the Window for the view is only created after the view is
 104      * realized with W_RealizeView()
 105      *
 106      * Consider the returned view as read-only.
 107      */
 108     mPtr->view = W_CreateView(W_VIEW(parent));
 109     if (!mPtr->view) {
 110         free(mPtr);
 111         return NULL;
 112     }
 113     /* always do this */
 114     mPtr->view->self = mPtr;
 115
 116     /*
 117      * Intercept some events for our widget, so that we can handle them.
 118      */
 119     WMCreateEventHandler(mPtr->view, ExposureMask /* this allows us to know when we should paint */
 120                          |StructureNotifyMask, /* this allows us to know things like when we are destroyed */
 121                          handleEvents, mPtr);
 122
 123     /*
 124      * Intercept some other events. This could be merged with the above
 125      * call, but we separate for more organization.
 126      */
 127     WMCreateEventHandler(mPtr->view, ButtonPressMask,handleActionEvents, mPtr);
 128
 129     return mPtr;
 130 }
 131
 132
 133
 134 /*
 135  * Paint our widget contents.
 136  */
 137 static void
 138 paintMyWidget(_MyWidget *mPtr)
 139 {
 140     W_Screen *scr = mPtr->view->screen;
 141     WMColor *color;
 142
 143
 144     if (mPtr->text) {
 145
 146         color = WMWhiteColor(scr);
 147
 148         W_PaintText(mPtr->view, mPtr->view->window, scr->normalFont,  0, 0,
 149                     mPtr->view->size.width, WACenter, WMColorGC(color),
 150                     False, mPtr->text, strlen(mPtr->text));
 151
 152         WMReleaseColor(color);
 153     }
 154 }
 155
 156
 157
 158 static void
 159 handleEvents(XEvent *event, void *data)
 160 {
 161     _MyWidget *mPtr = (_MyWidget*)data;
 162
 163
 164     switch (event->type) {
 165      case Expose:
 166         if (event->xexpose.count!=0)
 167             break;
 168         paintMyWidget(mPtr);
 169         break;
 170
 171      case DestroyNotify:
 172         destroyMyWidget(mPtr);
 173         break;
 174
 175     }
 176 }
 177
 178
 179 static void
 180 handleActionEvents(XEvent *event, void *data)
 181 {
 182     _MyWidget *mPtr = (_MyWidget*)data;
 183
 184     switch (event->type) {
 185      case ButtonPress:
 186         XBell(mPtr->view->screen->display, 100);
 187         XBell(mPtr->view->screen->display, 100);
 188         break;
 189     }
 190 }
 191
 192
 193 void
 194 SetMyWidgetText(MyWidget *mPtr, char *text)
 195 {
 196     CHECK_CLASS(mPtr, myWidgetClass);
 197
 198     if (mPtr->text)
 199         free(mPtr->text);
 200
 201     mPtr->text = wstrdup(text);
 202
 203     if (W_VIEW_MAPPED(mPtr->view)) {
 204         paintMyWidget(mPtr);
 205     }
 206 }
 207
 208
 209
 210 static void
 211 destroyMyWidget(_MyWidget *mPtr)
 212 {
 213     /*
 214      * Free all data we allocated for our widget.
 215      */
 216
 217     if (mPtr->text)
 218         free(mPtr->text);
 219
 220     free(mPtr);
 221 }
 222
 223