add RPN calculator demo

examples/basic/calculator.c

@@ -0,0 +1,185 @@
+#include <Mw/Milsko.h>
+
+MwWidget widgets[18];
+MwWidget inp;
+
+/* probably enough for most tasks */
+double stack[512];
+int    sp = 0;
+
+static void resize(MwWidget handle, void* client, void* user) {
+	int ww = MwGetInteger(handle, MwNwidth);
+	int wh = MwGetInteger(handle, MwNheight) - MwGetInteger(inp, MwNheight);
+	int i;
+
+	MwVaApply(inp,
+		  MwNwidth, ww,
+		  NULL);
+
+	for(i = 0; i < sizeof(widgets) / sizeof(widgets[0]); i++) {
+		int x = i % 4;
+		int y = i / 4;
+		if(widgets[i] != NULL) {
+			MwVaApply(widgets[i],
+				  MwNwidth, ww / 4,
+				  MwNheight, wh / 5,
+				  MwNx, ww / 4 * x,
+				  MwNy, wh / 5 * y + MwGetInteger(inp, MwNheight),
+				  NULL);
+		}
+	}
+}
+
+static void activate(MwWidget handle, void* client, void* user) {
+	const char* n = MwGetText(handle, MwNtext);
+
+	if(('0' <= n[0] && n[0] <= '9') || n[0] == '.') {
+		const char* s = MwGetText(inp, MwNtext);
+		char*	    r;
+
+		if(n[0] == '.' && s != NULL) {
+			int i;
+			for(i = 0; s[i] != 0; i++) {
+				if(s[i] == '.') return;
+			}
+		}
+
+		if(s == NULL) s = "";
+
+		r = MwStringConcat(s, n);
+		MwVaApply(inp,
+			  MwNtext, r,
+			  NULL);
+		free(r);
+	} else if(n[0] == 'E') {
+		const char* s = MwGetText(inp, MwNtext);
+
+		if(s != NULL) {
+			stack[sp++] = atof(s);
+
+			MwVaApply(inp,
+				  MwNtext, "",
+				  NULL);
+		}
+	} else if(n[0] == 'C') {
+		MwVaApply(inp,
+			  MwNtext, "",
+			  NULL);
+	} else if(n[0] == '+' || n[0] == '-' || n[0] == '*' || n[0] == '/') {
+		if(sp >= 2) {
+			double sv = stack[--sp];
+			double fv = stack[--sp];
+			double v;
+			char   buf[256];
+
+			if(n[0] == '+') {
+				v = fv + sv;
+			} else if(n[0] == '-') {
+				v = fv - sv;
+			} else if(n[0] == '*') {
+				v = fv * sv;
+			} else if(n[0] == '/') {
+				v = fv / sv;
+			}
+
+			sprintf(buf, "%g", v);
+
+			MwVaApply(inp,
+				  MwNtext, buf,
+				  NULL);
+		}
+	}
+}
+
+int main() {
+	MwWidget w;
+	int	 i;
+
+	for(i = 0; i < sizeof(widgets) / sizeof(widgets[0]); i++) widgets[i] = NULL;
+
+	MwLibraryInit();
+
+	w = MwVaCreateWidget(MwWindowClass, "main", NULL, MwDEFAULT, MwDEFAULT, 150, 150,
+			     MwNtitle, "Calculator",
+			     NULL);
+
+	inp = MwCreateWidget(MwEntryClass, "entry", w, 0, 0, 0, 24);
+
+	widgets[0] = MwVaCreateWidget(MwButtonClass, "7", w, 0, 0, 0, 0,
+				      MwNtext, "7",
+				      NULL);
+
+	widgets[1] = MwVaCreateWidget(MwButtonClass, "8", w, 0, 0, 0, 0,
+				      MwNtext, "8",
+				      NULL);
+
+	widgets[2] = MwVaCreateWidget(MwButtonClass, "9", w, 0, 0, 0, 0,
+				      MwNtext, "9",
+				      NULL);
+
+	widgets[3] = MwVaCreateWidget(MwButtonClass, "/", w, 0, 0, 0, 0,
+				      MwNtext, "/",
+				      NULL);
+
+	widgets[4] = MwVaCreateWidget(MwButtonClass, "4", w, 0, 0, 0, 0,
+				      MwNtext, "4",
+				      NULL);
+
+	widgets[5] = MwVaCreateWidget(MwButtonClass, "5", w, 0, 0, 0, 0,
+				      MwNtext, "5",
+				      NULL);
+
+	widgets[6] = MwVaCreateWidget(MwButtonClass, "6", w, 0, 0, 0, 0,
+				      MwNtext, "6",
+				      NULL);
+
+	widgets[7] = MwVaCreateWidget(MwButtonClass, "*", w, 0, 0, 0, 0,
+				      MwNtext, "*",
+				      NULL);
+
+	widgets[8] = MwVaCreateWidget(MwButtonClass, "1", w, 0, 0, 0, 0,
+				      MwNtext, "1",
+				      NULL);
+
+	widgets[9] = MwVaCreateWidget(MwButtonClass, "2", w, 0, 0, 0, 0,
+				      MwNtext, "2",
+				      NULL);
+
+	widgets[10] = MwVaCreateWidget(MwButtonClass, "3", w, 0, 0, 0, 0,
+				       MwNtext, "3",
+				       NULL);
+
+	widgets[11] = MwVaCreateWidget(MwButtonClass, "-", w, 0, 0, 0, 0,
+				       MwNtext, "-",
+				       NULL);
+
+	widgets[12] = MwVaCreateWidget(MwButtonClass, "0", w, 0, 0, 0, 0,
+				       MwNtext, "0",
+				       NULL);
+
+	widgets[13] = MwVaCreateWidget(MwButtonClass, ".", w, 0, 0, 0, 0,
+				       MwNtext, ".",
+				       NULL);
+
+	widgets[16] = MwVaCreateWidget(MwButtonClass, "E", w, 0, 0, 0, 0,
+				       MwNtext, "E",
+				       NULL);
+
+	widgets[15] = MwVaCreateWidget(MwButtonClass, "+", w, 0, 0, 0, 0,
+				       MwNtext, "+",
+				       NULL);
+
+	widgets[17] = MwVaCreateWidget(MwButtonClass, "C", w, 0, 0, 0, 0,
+				       MwNtext, "C",
+				       NULL);
+
+	for(i = 0; i < sizeof(widgets) / sizeof(widgets[0]); i++) {
+		if(widgets[i] != NULL) MwAddUserHandler(widgets[i], MwNactivateHandler, activate, NULL);
+	}
+
+	MwAddUserHandler(w, MwNresizeHandler, resize, NULL);
+
+	resize(w, NULL, NULL);
+
+	MwLoop(w);
+}

pl/rules.pl

@@ -128,6 +128,7 @@ new_example("examples/basic/treeview");
 new_example("examples/basic/box");
 new_example("examples/basic/clipboard");
 new_example("examples/basic/sevensegment");
+new_example("examples/basic/calculator");
 
 if (param_get("opengl")) {
     new_example("examples/gldemos/boing",    $gl_libs);