Show Tile Inspector hint when nothing is selected

data/language/en-GB.txt

@@ -3602,6 +3602,7 @@ STR_6493    :This park was saved in a later version of OpenRCT2, some data may b
 STR_6494    :Group by ride type
 STR_6495    :Group rides by ride types instead of showing each vehicle separately.
 STR_6496    :{WINDOW_COLOUR_2}{STRINGID}
+STR_6497    :Click on a tile to show its tile elements.{NEWLINE}Ctrl + click a tile element to select it directly.
 
 #############
 # Scenarios #

distribution/changelog.txt

@@ -12,6 +12,7 @@
 - Improved: [#16992] The checkbox in the visibility column of the Tile Inspector has been replaced with an eye symbol.
 - Improved: [#16999] The maximum price for the park entry has been raised to £999.
 - Improved: [#17050] Transparency can be enabled directly without needing see-through enabled first.
+- Improved: [#17059] Show Tile Inspector usage hint when nothing is selected.
 - Removed: [#16864] Title sequence editor (replaced by plug-in).
 
 0.4.0 (2022-04-25)

src/openrct2-ui/windows/TileInspector.cpp

@@ -1301,7 +1301,8 @@ static void WindowTileInspectorToolDrag(rct_window* w, rct_widgetindex widgetInd
 static void WindowTileInspectorScrollgetsize(rct_window* w, int32_t scrollIndex, int32_t* width, int32_t* height)
 {
     *width = WW - 30;
-    *height = windowTileInspectorElementCount * SCROLLABLE_ROW_HEIGHT;
+    *height = w->widgets[WIDX_LIST].height() - 2;
+    *height = std::max(windowTileInspectorElementCount * SCROLLABLE_ROW_HEIGHT, *height);
 }
 
 static void WindowTileInspectorSetPage(rct_window* w, const TileInspectorPage page)
@@ -2258,14 +2259,23 @@ static void WindowTileInspectorScrollpaint(rct_window* w, rct_drawpixelinfo* dpi
         dpi, { { dpi->x, dpi->y }, { dpi->x + dpi->width - 1, dpi->y + dpi->height - 1 } },
         ColourMapA[w->colours[1]].mid_light);
 
+    // Show usage hint when nothing is selected
+    if (!windowTileInspectorTileSelected)
+    {
+        auto& listWidget = w->widgets[WIDX_LIST];
+        auto centrePos = ScreenCoordsXY{ listWidget.width() / 2,
+                                         (listWidget.height() - font_get_line_height(FontSpriteBase::MEDIUM)) / 2 };
+        auto ft = Formatter{};
+        auto textPaint = TextPaint{ w->colours[1], TextAlignment::CENTRE };
+        DrawTextWrapped(dpi, centrePos, listWidth, STR_TILE_INSPECTOR_SELECT_TILE_HINT, ft, textPaint);
+        return;
+    }
+
     ScreenCoordsXY screenCoords{};
     screenCoords.y = SCROLLABLE_ROW_HEIGHT * (windowTileInspectorElementCount - 1);
     int32_t i = 0;
     char buffer[256];
 
-    if (!windowTileInspectorTileSelected)
-        return;
-
     const TileElement* tileElement = map_get_first_element_at(windowTileInspectorToolMap);
 
     do

src/openrct2/localisation/StringIds.h

@@ -3874,6 +3874,8 @@ enum : uint16_t
     STR_GROUP_BY_TRACK_TYPE_TIP = 6495,
     STR_NEW_RIDE_VEHICLE_NAME = 6496,
 
+    STR_TILE_INSPECTOR_SELECT_TILE_HINT = 6497,
+
     // Have to include resource strings (from scenarios and objects) for the time being now that language is partially working
     /* MAX_STR_COUNT = 32768 */ // MAX_STR_COUNT - upper limit for number of strings, not the current count strings
 };