1 files changed, 106 insertions, 0 deletions
diff --git a/textscreen/txt_widget.c b/textscreen/txt_widget.c
index c10699b5..d257ee75 100644
--- a/textscreen/txt_widget.c
+++ b/textscreen/txt_widget.c
@@ -1,7 +1,111 @@
 #include <stdlib.h>
+#include <string.h>
 
 #include "txt_widget.h"
 
+typedef struct
+{
+    char *signal_name;
+    TxtWidgetSignalFunc func;
+    void *user_data;
+} txt_callback_t;
+
+struct txt_callback_table_s
+{
+    txt_callback_t *callbacks;
+    int num_callbacks;
+};
+
+txt_callback_table_t *TXT_NewCallbackTable(void)
+{
+    txt_callback_table_t *table;
+
+    table = malloc(sizeof(txt_callback_table_t));
+    table->callbacks = NULL;
+    table->num_callbacks = 0;
+
+    return table;
+}
+
+void TXT_DestroyCallbackTable(txt_callback_table_t *table)
+{
+    int i;
+
+    for (i=0; i<table->num_callbacks; ++i)
+    {
+        free(table->callbacks[i].signal_name);
+    }
+    
+    free(table->callbacks);
+    free(table);
+}
+
+void TXT_InitWidget(void *uncast_widget, txt_widget_class_t *widget_class)
+{
+    txt_widget_t *widget = (txt_widget_t *) uncast_widget;
+
+    widget->widget_class = widget_class;
+    widget->callback_table = TXT_NewCallbackTable();
+
+    // Default values: visible and selectable
+
+    widget->selectable = 1;
+    widget->visible = 1;
+}
+
+void TXT_SignalConnect(txt_widget_t *widget, 
+                       char *signal_name,
+                       TxtWidgetSignalFunc func, 
+                       void *user_data)
+{
+    txt_callback_table_t *table;
+    txt_callback_t *callback;
+    int i;
+
+    table = widget->callback_table;
+
+    for (i=0; i<table->num_callbacks; ++i)
+    {
+        if (!strcmp(signal_name, table->callbacks[i].signal_name))
+        {
+            // Replace existing signal
+
+            table->callbacks[i].func = func;
+            table->callbacks[i].user_data = user_data;
+            break;
+        }
+    }
+
+    // Add a new callback to the table
+
+    table->callbacks 
+            = realloc(table->callbacks,
+                      sizeof(txt_callback_t) * (table->num_callbacks + 1));
+    callback = &table->callbacks[table->num_callbacks];
+    ++table->num_callbacks;
+
+    callback->signal_name = strdup(signal_name);
+    callback->func = func;
+    callback->user_data = user_data;
+}
+
+void TXT_EmitSignal(txt_widget_t *widget, char *signal_name)
+{
+    txt_callback_table_t *table;
+    int i;
+
+    table = widget->callback_table;
+
+    for (i=0; i<table->num_callbacks; ++i)
+    {
+        if (!strcmp(table->callbacks[i].signal_name, signal_name))
+        {
+            table->callbacks[i].func(widget, table->callbacks[i].user_data);
+            break;
+        }
+    }
+}
+
 void TXT_CalcWidgetSize(txt_widget_t *widget, int *w, int *h)
 {
     return widget->widget_class->size_calc(widget, w, h);
@@ -15,6 +119,8 @@ void TXT_DrawWidget(txt_widget_t *widget, int w, int selected)
 void TXT_DestroyWidget(txt_widget_t *widget)
 {
     widget->widget_class->destructor(widget);
+    TXT_DestroyCallbackTable(widget->callback_table);
+    free(widget);
 }
 
 int TXT_WidgetKeyPress(txt_widget_t *widget, int key)