Add dropdown listbox widget

Subversion-branch: /trunk/chocolate-doom
Subversion-revision: 578

1 files changed, 263 insertions, 0 deletions

diff --git a/textscreen/txt_dropdown.c b/textscreen/txt_dropdown.c
new file mode 100644
index 00000000..84fd3aca
--- /dev/null
+++ b/textscreen/txt_dropdown.c
@@ -0,0 +1,263 @@
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "doomkeys.h"
+
+#include "txt_button.h"
+#include "txt_dropdown.h"
+#include "txt_io.h"
+#include "txt_main.h"
+#include "txt_window.h"
+
+typedef struct 
+{
+    txt_window_t *window;
+    txt_dropdown_list_t *list;
+    int item;
+} callback_data_t;
+
+// Check if the selected value for a list is valid
+
+static int ValidSelection(txt_dropdown_list_t *list)
+{
+    return *list->variable >= 0 && *list->variable < list->num_values;
+}
+
+// Calculate the Y position for the selector window
+
+static int SelectorWindowY(txt_dropdown_list_t *list)
+{
+    if (ValidSelection(list))
+    {
+        return list->widget.y - 1 - *list->variable;
+    }
+    else
+    {
+        return list->widget.y - 1 - (list->num_values / 2);
+    }
+}
+
+// Called when a button in the selector window is pressed
+
+static void ItemSelected(TXT_UNCAST_ARG(button), TXT_UNCAST_ARG(callback_data))
+{
+    TXT_CAST_ARG(callback_data_t, callback_data);
+
+    // Set the variable
+
+    *callback_data->list->variable = callback_data->item;
+
+    // Close the window
+
+    TXT_CloseWindow(callback_data->window);
+}
+
+// Free callback data when the window is closed
+
+static void FreeCallbackData(TXT_UNCAST_ARG(list), 
+                             TXT_UNCAST_ARG(callback_data))
+{
+    TXT_CAST_ARG(callback_data_t, callback_data);
+
+    free(callback_data);
+}
+
+// Catch presses of escape and close the window.
+
+static int SelectorWindowListener(txt_window_t *window, int key, void *user_data)
+{
+    if (key == KEY_ESCAPE)
+    {
+        TXT_CloseWindow(window);
+        return 1;
+    }
+
+    return 0;
+}
+
+// Open the dropdown list window to select an item
+
+static void OpenSelectorWindow(txt_dropdown_list_t *list)
+{
+    txt_window_t *window;
+    int i;
+
+    // Open a simple window with no title bar or action buttons.
+
+    window = TXT_NewWindow(NULL);
+
+    TXT_SetWindowAction(window, TXT_HORIZ_LEFT, NULL);
+    TXT_SetWindowAction(window, TXT_HORIZ_CENTER, NULL);
+    TXT_SetWindowAction(window, TXT_HORIZ_RIGHT, NULL);
+
+    // Position the window so that the currently selected item appears
+    // over the top of the list widget.
+
+    TXT_SetWindowPosition(window, TXT_HORIZ_LEFT, TXT_VERT_TOP,
+                          list->widget.x - 2, SelectorWindowY(list));
+
+    // Add a button to the window for each option in the list.
+
+    for (i=0; i<list->num_values; ++i)
+    {
+        txt_button_t *button;
+        callback_data_t *data;
+
+        button = TXT_NewButton(list->values[i]);
+
+        TXT_AddWidget(window, button);
+
+        // Callback struct
+
+        data = malloc(sizeof(callback_data_t));
+        data->list = list;
+        data->window = window;
+        data->item = i;
+        
+        // When the button is pressed, invoke the button press callback
+       
+        TXT_SignalConnect(button, "pressed", ItemSelected, data);
+        
+        // When the window is closed, free back the callback struct
+
+        TXT_SignalConnect(window, "closed", FreeCallbackData, data);
+
+        // Is this the currently-selected value?  If so, select the button
+        // in the window as the default.
+        
+        if (i == *list->variable)
+        {
+            TXT_SelectWidget(window, button);
+        }
+    }
+
+    // Catch presses of escape in this window and close it.
+
+    TXT_SetKeyListener(window, SelectorWindowListener, NULL);
+}
+
+static int DropdownListWidth(txt_dropdown_list_t *list)
+{
+    int i;
+    int result;
+
+    // Find the maximum string width
+ 
+    result = 0;
+
+    for (i=0; i<list->num_values; ++i)
+    {
+        int w = strlen(list->values[i]);
+        if (w > result) 
+        {
+            result = w;
+        }
+    }
+
+    return result;
+}
+
+static void TXT_DropdownListSizeCalc(TXT_UNCAST_ARG(list))
+{
+    TXT_CAST_ARG(txt_dropdown_list_t, list);
+
+    list->widget.w = DropdownListWidth(list);
+    list->widget.h = 1;
+}
+
+static void TXT_DropdownListDrawer(TXT_UNCAST_ARG(list), int selected)
+{
+    TXT_CAST_ARG(txt_dropdown_list_t, list);
+    int i;
+    char *str;
+
+    // Set bg/fg text colors.
+
+    if (selected) 
+    {
+        TXT_BGColor(TXT_COLOR_GREY, 0);
+    }
+    else
+    {
+        TXT_BGColor(TXT_COLOR_BLUE, 0);
+    }
+
+    TXT_FGColor(TXT_COLOR_BRIGHT_WHITE);
+
+    // Select a string to draw from the list, if the current value is
+    // in range.  Otherwise fall back to a default.
+
+    if (ValidSelection(list))
+    {
+        str = list->values[*list->variable];
+    }
+    else
+    {
+        str = "???";
+    }
+
+    // Draw the string and fill to the end with spaces
+
+    TXT_DrawString(str);
+
+    for (i=strlen(str); i<list->widget.w; ++i) 
+    {
+        TXT_DrawString(" ");
+    }
+}
+
+static void TXT_DropdownListDestructor(TXT_UNCAST_ARG(list))
+{
+}
+
+static int TXT_DropdownListKeyPress(TXT_UNCAST_ARG(list), int key)
+{
+    TXT_CAST_ARG(txt_dropdown_list_t, list);
+
+    if (key == KEY_ENTER)
+    {
+        OpenSelectorWindow(list);
+        return 1;
+    }
+    
+    return 0;
+}
+
+static void TXT_DropdownListMousePress(TXT_UNCAST_ARG(list), 
+                                       int x, int y, int b)
+{
+    TXT_CAST_ARG(txt_dropdown_list_t, list);
+
+    // Left mouse click does the same as selecting and pressing enter
+
+    if (b == TXT_MOUSE_LEFT)
+    {
+        TXT_DropdownListKeyPress(list, KEY_ENTER);
+    }
+}
+
+txt_widget_class_t txt_dropdown_list_class =
+{
+    TXT_DropdownListSizeCalc,
+    TXT_DropdownListDrawer,
+    TXT_DropdownListKeyPress,
+    TXT_DropdownListDestructor,
+    TXT_DropdownListMousePress,
+};
+
+txt_dropdown_list_t *TXT_NewDropdownList(int *variable, char **values, 
+                                         int num_values)
+{
+    txt_dropdown_list_t *list;
+
+    list = malloc(sizeof(txt_dropdown_list_t));
+
+    TXT_InitWidget(list, &txt_dropdown_list_class);
+    list->variable = variable;
+    list->values = values;
+    list->num_values = num_values;
+
+    return list;
+}
+