Use better text descriptions. Holding down rate buttons now increase/decrease

data/language/en-GB.txt

@@ -4201,6 +4201,8 @@ STR_5889    :Custom currency symbol
 STR_5890    :Enter the currency symbol to display
 STR_5891    :Default
 STR_5892    :{SMALLFONT}{BLACK}Go to the default directory
+STR_5893    :Exchange Rate
+STR_5894    :Enter the exchange rate
 
 #############
 # Scenarios #

src/localisation/currency.h

@@ -49,6 +49,7 @@ typedef enum {
 } CURRENCY_AFFIX;
 
 #define CURRENCY_SYMBOL_MAX_SIZE 8
+#define CURRENCY_RATE_MAX_NUM_DIGITS 9
 
 // Currency format specification - inspired by OpenTTD
 typedef struct currency_descriptor {

src/localisation/string_ids.h

@@ -2672,6 +2672,8 @@ enum {
 	STR_LOADSAVE_DEFAULT = 5891,
 	STR_LOADSAVE_DEFAULT_TIP = 5892,
 
+	STR_RATE_INPUT_TITLE = 5893,
+	STR_RATE_INPUT_DESC = 5894,
 	// Have to include resource strings (from scenarios and objects) for the time being now that language is partially working
 	STR_COUNT = 32768
 };

src/windows/custom_currency.c

@@ -115,6 +115,7 @@ void custom_currency_window_open()
 		(1 << WIDX_AFFIX_DROPDOWN) |
 		(1 << WIDX_AFFIX_DROPDOWN_BUTTON);
 
+	window->hold_down_widgets = (1 << WIDX_RATE_UP) | (1 << WIDX_RATE_DOWN);
 	window_init_scroll_widgets(window);
 	window->colours[0] = 22;
 	window->colours[1] = 22;
@@ -192,13 +193,14 @@ static void custom_currency_window_mouseup(rct_window *w, int widgetIndex)
 {
 	switch(widgetIndex) {
 	case WIDX_RATE:
-		window_text_input_raw_open(
+		window_text_input_open(
 			w,
 			WIDX_RATE,
-			STR_CUSTOM_CURRENCY_SYMBOL_INPUT_TITLE,
-			STR_CUSTOM_CURRENCY_SYMBOL_INPUT_DESC,
-			CurrencyDescriptors[CURRENCY_CUSTOM].symbol_unicode,
-			CURRENCY_SYMBOL_MAX_SIZE
+			STR_RATE_INPUT_TITLE,
+			STR_RATE_INPUT_DESC,
+			5182,
+			(uint32)CurrencyDescriptors[CURRENCY_CUSTOM].rate,
+			CURRENCY_RATE_MAX_NUM_DIGITS
 		);
 		break;
 	}