Implement dummy JavaScript engine just for the sake of viewing calc.pdf

5 files changed, 321 insertions, 12 deletions

diff --git a/pdf/mupdf-internal.h b/pdf/mupdf-internal.h
index d0617769..8ffb81f1 100644
--- a/pdf/mupdf-internal.h
+++ b/pdf/mupdf-internal.h
@@ -568,11 +568,15 @@ void *pdf_find_item(fz_context *ctx, fz_store_free_fn *free, pdf_obj *key);
 void pdf_remove_item(fz_context *ctx, fz_store_free_fn *free, pdf_obj *key);
 
 /*
- * Javascript engine interface
+ * Javascript handler
  */
 pdf_js *pdf_new_js(pdf_document *doc);
 void pdf_drop_js(pdf_js *js);
+void pdf_js_execute(pdf_js *js, char *code);
 
+/*
+ * Javascript engine interface
+ */
 typedef struct pdf_jsimp_s pdf_jsimp;
 typedef struct pdf_jsimp_type_s pdf_jsimp_type;
 typedef struct pdf_jsimp_obj_s pdf_jsimp_obj;
@@ -596,4 +600,6 @@ void pdf_jsimp_set_this(pdf_jsimp *imp, pdf_jsimp_obj *obj);
 pdf_jsimp_obj *pdf_jsimp_fromString(pdf_jsimp *imp, char *str);
 char *pdf_jsimp_toString(pdf_jsimp *imp, pdf_jsimp_obj *obj);
 
+void pdf_jsimp_execute(pdf_jsimp *imp, char *code);
+
 #endif
diff --git a/pdf/pdf_form.c b/pdf/pdf_form.c
index d1bc7576..31e1ce49 100644
--- a/pdf/pdf_form.c
+++ b/pdf/pdf_form.c
@@ -580,6 +580,26 @@ void pdf_synthesize_missing_appearance(pdf_document *doc, pdf_obj *obj)
 	}
 }
 
+static void execute_action(pdf_document *doc, pdf_obj *obj)
+{
+	pdf_obj *a;
+
+	a = pdf_dict_gets(obj, "A");
+	while (a)
+	{
+		char *type = pdf_to_name(pdf_dict_gets(a, "S"));
+
+		if (!strcmp(type, "JavaScript"))
+		{
+			pdf_obj *js = pdf_dict_gets(a, "JS");
+			if (js)
+				pdf_js_execute(doc->js, pdf_to_str_buf(js));
+		}
+
+		a = pdf_dict_gets(a, "Next");
+	}
+}
+
 static void toggle_check_box(pdf_document *doc, pdf_obj *obj)
 {
 	pdf_obj *as;
@@ -673,6 +693,8 @@ int pdf_pass_event(pdf_document *doc, pdf_page *page, fz_ui_event *ui_event)
 						changed = 1;
 						break;
 					}
+
+					execute_action(doc, annot->obj);
 				}
 				break;
 			}
diff --git a/pdf/pdf_js.c b/pdf/pdf_js.c
index 4c2e30ab..408f7bf2 100644
--- a/pdf/pdf_js.c
+++ b/pdf/pdf_js.c
@@ -46,7 +46,7 @@ static pdf_jsimp_obj *doc_getField(void *jsctx, void *obj, int argc, pdf_jsimp_o
 		pdf_obj *t;
 		field = pdf_array_get(js->form, i);
 		t = pdf_dict_gets(field, "T");
-		if (!strcmp(name, pdf_to_name(t)))
+		if (!strcmp(name, pdf_to_str_buf(t)))
 			break;
 	}
 
@@ -111,4 +111,9 @@ void pdf_drop_js(pdf_js *js)
 		pdf_drop_jsimp(js->imp);
 		fz_free(ctx, js);
 	}
+}
+
+void pdf_js_execute(pdf_js *js, char *code)
+{
+	pdf_jsimp_execute(js->imp, code);
 }
\ No newline at end of file
diff --git a/pdf/pdf_jsimp.c b/pdf/pdf_jsimp.c
index 080b1df4..c0a11c58 100644
--- a/pdf/pdf_jsimp.c
+++ b/pdf/pdf_jsimp.c
@@ -1,59 +1,335 @@
+/*
+ * This is a dummy JavaScript engine. It cheats by recognising the specific
+ * strings in calc.pdf, and hence will work only for that file. It is for
+ * testing only.
+ */
+
+
 #include "fitz-internal.h"
 #include "mupdf-internal.h"
 
+enum
+{
+	FUNC_NONE,
+	FUNC_PLUS,
+	FUNC_MINUS,
+	FUNC_MULT,
+	FUNC_DIV
+};
+
 struct pdf_jsimp_s
 {
-	int x;
+	fz_context *ctx;
+	void       *jsctx;
+	double accum;
+	double entry;
+	double multiplier;
+	double divisor;
+	int func;
+	pdf_jsimp_obj *jsthis;
+	pdf_jsimp_obj *display;
+	pdf_jsimp_obj *funcfield;
 };
 
+/* We need only a couple of specific methods for calc.pdf */
 struct pdf_jsimp_type_s
 {
-	int x;
+	pdf_jsimp_dtr    *dtr;
+	pdf_jsimp_method *getField;
+	pdf_jsimp_getter *getValue;
+	pdf_jsimp_setter *setValue;
 };
 
 struct pdf_jsimp_obj_s
 {
-	int x;
+	pdf_jsimp_type *type;
+	void *obj;
 };
 
 
+static double digit_button(pdf_jsimp *imp, int digit)
+{
+	imp->entry = imp->entry * imp->multiplier + digit / imp->divisor;
+
+	if (imp->divisor >= 10)
+	{
+		imp->divisor = imp->divisor * 10;
+	}
+	else
+	{
+		imp->multiplier = 10;
+	}
+
+	return imp->entry;
+}
+
+static void assign_display_value(pdf_jsimp *imp, double val)
+{
+	char valstr[256];
+	pdf_jsimp_obj *valobj;
+
+	if (imp->display == NULL)
+	{
+		pdf_jsimp_obj *str_arg = pdf_jsimp_fromString(imp, "Display");
+		pdf_jsimp_obj *doc = imp->jsthis;
+		imp->display = doc->type->getField(imp->jsctx, doc->obj, 1, &str_arg);
+	}
+
+	snprintf(valstr, sizeof(valstr), "%f", val);
+	if (imp->display && imp->display->type->setValue)
+	{
+		valobj = pdf_jsimp_fromString(imp, valstr);
+		imp->display->type->setValue(imp->jsctx, imp->display->obj, valobj);
+	}
+}
+
+static void assign_func_value(pdf_jsimp *imp, int val)
+{
+	pdf_jsimp_obj *valobj = NULL;
+
+	if (imp->funcfield == NULL)
+	{
+		pdf_jsimp_obj *str_arg = pdf_jsimp_fromString(imp, "Func");
+		pdf_jsimp_obj *doc = imp->jsthis;
+		imp->funcfield = doc->type->getField(imp->jsctx, doc->obj, 1, &str_arg);
+	}
+
+	if (imp->funcfield && imp->funcfield->type->setValue)
+	{
+		switch(val)
+		{
+		case FUNC_NONE:
+			valobj = pdf_jsimp_fromString(imp, "");
+			break;
+		case FUNC_MULT:
+			valobj = pdf_jsimp_fromString(imp, "MULT");
+			break;
+		case FUNC_DIV:
+			valobj = pdf_jsimp_fromString(imp, "DIV");
+			break;
+		case FUNC_PLUS:
+			valobj = pdf_jsimp_fromString(imp, "PLUS");
+			break;
+		case FUNC_MINUS:
+			valobj = pdf_jsimp_fromString(imp, "MINUS");
+			break;
+		}
+
+		if (valobj)
+			imp->funcfield->type->setValue(imp->jsctx, imp->funcfield->obj, valobj);
+	}
+}
+
+static void clear_entry(pdf_jsimp *imp)
+{
+	imp->entry = 0;
+	imp->multiplier = 1;
+	imp->divisor = 1;
+}
+
+static void update_result(pdf_jsimp *imp)
+{
+	switch(imp->func)
+	{
+	case FUNC_PLUS:
+		imp->accum = imp->accum + imp->entry;
+		break;
+	case FUNC_MINUS:
+		imp->accum = imp->accum - imp->entry;
+		break;
+	case FUNC_MULT:
+		imp->accum = imp->accum * imp->entry;
+		break;
+	case FUNC_DIV:
+		if (imp->entry != 0)
+			imp->accum = imp->accum / imp->entry;
+		break;
+	}
+
+	imp->func = FUNC_NONE;
+	assign_func_value(imp, FUNC_NONE);
+	clear_entry(imp);
+}
+
+static void func_button(pdf_jsimp *imp, int func)
+{
+	if (imp->func != FUNC_NONE)
+	{
+		update_result(imp);
+	}
+	else
+	{
+		if (imp->entry != 0)
+			imp->accum = imp->entry;
+
+		imp->func = func;
+		assign_func_value(imp, func);
+		clear_entry(imp);
+	}
+}
+
+static void all_cancel(pdf_jsimp *imp)
+{
+	clear_entry(imp);
+	assign_display_value(imp, 0);
+	imp->accum = 0;
+	assign_func_value(imp, FUNC_NONE);
+}
+
 pdf_jsimp *pdf_new_jsimp(fz_context *ctx, void *jsctx)
 {
-	return NULL;
+	pdf_jsimp *imp = fz_malloc_struct(ctx, pdf_jsimp);
+
+	imp->ctx = ctx;
+	imp->jsctx = jsctx;
+	imp->accum = 0;
+	imp->entry = 0;
+	imp->divisor = 1;
+	imp->multiplier = 1;
+
+	return imp;
 }
 
 void pdf_drop_jsimp(pdf_jsimp *imp)
 {
+	if (imp)
+	{
+		fz_free(imp->ctx, imp);
+	}
 }
 
 pdf_jsimp_type *pdf_jsimp_new_type(pdf_jsimp *imp, pdf_jsimp_dtr *dtr)
 {
-	return NULL;
+	pdf_jsimp_type *type = fz_malloc_struct(imp->ctx, pdf_jsimp_type);
+	type->dtr = dtr;
+
+	return type;
 }
 
 void pdf_jsimp_addmethod(pdf_jsimp *imp, pdf_jsimp_type *type, char *name, pdf_jsimp_method *meth)
 {
+	if (!strcmp(name, "getField"))
+	{
+		type->getField = meth;
+	}
 }
 
 void pdf_jsimp_addproperty(pdf_jsimp *imp, pdf_jsimp_type *type, char *name, pdf_jsimp_getter *get, pdf_jsimp_setter *set)
 {
+	if (!strcmp(name, "value"))
+	{
+		type->getValue = get;
+		type->setValue = set;
+	}
 }
 
-pdf_jsimp_obj *pdf_jsimp_new_obj(pdf_jsimp *imp, pdf_jsimp_type *type, void *obj)
+pdf_jsimp_obj *pdf_jsimp_new_obj(pdf_jsimp *imp, pdf_jsimp_type *type, void *natobj)
 {
-	return NULL;
+	pdf_jsimp_obj *obj = fz_malloc_struct(imp->ctx, pdf_jsimp_obj);
+	obj->type = type;
+	obj->obj  = natobj;
+
+	return obj;
 }
 
 void pdf_jsimp_set_this(pdf_jsimp *imp, pdf_jsimp_obj *obj)
 {
+	imp->jsthis = obj;
 }
 
+
 pdf_jsimp_obj *pdf_jsimp_fromString(pdf_jsimp *imp, char *str)
 {
-	return NULL;
+	/* Represent a string object as a pdf_jsimp_obj with a NULL type */
+	pdf_jsimp_obj *obj = fz_malloc_struct(imp->ctx, pdf_jsimp_obj);
+	obj->obj = fz_strdup(imp->ctx, str);
+
+	return obj;
 }
 
 char *pdf_jsimp_toString(pdf_jsimp *imp, pdf_jsimp_obj *obj)
 {
-	return NULL;
+	return (char *)(obj->type ? NULL : obj->obj);
+}
+
+void pdf_jsimp_execute(pdf_jsimp *imp, char *code)
+{
+	if (!strcmp(code, "display.value = digit_button(0);"))
+	{
+		assign_display_value(imp, digit_button(imp, 0));
+	}
+	else if (!strcmp(code, "display.value = digit_button(1);\r"))
+	{
+		assign_display_value(imp, digit_button(imp, 1));
+	}
+	else if (!strcmp(code, "display.value = digit_button(2)"))
+	{
+		assign_display_value(imp, digit_button(imp, 2));
+	}
+	else if (!strcmp(code, "display.value = digit_button(3)"))
+	{
+		assign_display_value(imp, digit_button(imp, 3));
+	}
+	else if (!strcmp(code, "display.value = digit_button(4)"))
+	{
+		assign_display_value(imp, digit_button(imp, 4));
+	}
+	else if (!strcmp(code, "display.value = digit_button(5)"))
+	{
+		assign_display_value(imp, digit_button(imp, 5));
+	}
+	else if (!strcmp(code, "display.value = digit_button(6);"))
+	{
+		assign_display_value(imp, digit_button(imp, 6));
+	}
+	else if (!strcmp(code, "display.value = digit_button(7);"))
+	{
+		assign_display_value(imp, digit_button(imp, 7));
+	}
+	else if (!strcmp(code, "display.value = digit_button(8);"))
+	{
+		assign_display_value(imp, digit_button(imp, 8));
+	}
+	else if (!strcmp(code, "display.value = digit_button(9);"))
+	{
+		assign_display_value(imp, digit_button(imp, 9));
+	}
+	else if (!strcmp(code, "if (divisor == 1) {\r divisor = 10;\r multiplier = 1;\r }"))
+	{
+		if (imp->divisor == 1)
+		{
+			imp->divisor = 10;
+			imp->multiplier = 1;
+		}
+	}
+	else if (!strcmp(code, "all_cancel();"))
+	{
+		all_cancel(imp);
+	}
+	else if (!strcmp(code, "clear_entry();\rdisplay.value = 0;"))
+	{
+		clear_entry(imp);
+		assign_display_value(imp, 0);
+	}
+	else if (!strcmp(code, "func_button(\"MULT\");"))
+	{
+		func_button(imp, FUNC_MULT);
+	}
+	else if (!strcmp(code, "func_button(\"DIV\");"))
+	{
+		func_button(imp, FUNC_DIV);
+	}
+	else if (!strcmp(code, "func_button(\"PLUS\");"))
+	{
+		func_button(imp, FUNC_PLUS);
+	}
+	else if (!strcmp(code, "func_button(\"MINUS\");"))
+	{
+		func_button(imp, FUNC_MINUS);
+	}
+	else if (!strcmp(code, "update_result();\rdisplay.value = accum;"))
+	{
+		update_result(imp);
+		assign_display_value(imp, imp->accum);
+	}
 }
\ No newline at end of file
diff --git a/pdf/pdf_xref.c b/pdf/pdf_xref.c
index e73ce72a..82407b80 100644
--- a/pdf/pdf_xref.c
+++ b/pdf/pdf_xref.c
@@ -690,8 +690,8 @@ pdf_open_document_with_stream(fz_stream *file)
 
 	fz_try(ctx)
 	{
-		xref->js = pdf_new_js(xref);
 		pdf_load_xref(xref, &xref->lexbuf.base);
+		xref->js = pdf_new_js(xref);
 	}
 	fz_catch(ctx)
 	{