Codechange: Move volume control slider logic to separate functions

5 files changed, 104 insertions, 34 deletions

diff --git a/src/music_gui.cpp b/src/music_gui.cpp
index 7e2aaac1d..469066706 100644
--- a/src/music_gui.cpp
+++ b/src/music_gui.cpp
@@ -26,6 +26,7 @@
 #include "settings_gui.h"
 #include "widgets/dropdown_func.h"
 #include "widgets/dropdown_type.h"
+#include "widgets/slider_func.h"
 
 #include "widgets/music_widget.h"
 
@@ -643,8 +644,6 @@ static void ShowMusicTrackSelection()
 }
 
 struct MusicWindow : public Window {
-	static const int slider_width = 3;
-
 	MusicWindow(WindowDesc *desc, WindowNumber number) : Window(desc)
 	{
 		this->InitNested(number);
@@ -740,27 +739,13 @@ struct MusicWindow : public Window {
 				break;
 			}
 
-			case WID_M_MUSIC_VOL: case WID_M_EFFECT_VOL: {
-				/* Draw a wedge indicating low to high volume level. */
-				const int ha = (r.bottom - r.top) / 5;
-				int wx1 = r.left, wx2 = r.right;
-				if (_current_text_dir == TD_RTL) std::swap(wx1, wx2);
-				const uint shadow = _colour_gradient[COLOUR_GREY][3];
-				const uint fill   = _colour_gradient[COLOUR_GREY][6];
-				const uint light  = _colour_gradient[COLOUR_GREY][7];
-				const std::vector<Point> wedge{ Point{wx1, r.bottom - ha}, Point{wx2, r.top + ha}, Point{wx2, r.bottom - ha} };
-				GfxFillPolygon(wedge, fill);
-				GfxDrawLine(wedge[0].x, wedge[0].y, wedge[2].x, wedge[2].y, light);
-				GfxDrawLine(wedge[1].x, wedge[1].y, wedge[2].x, wedge[2].y, _current_text_dir == TD_RTL ? shadow : light);
-				GfxDrawLine(wedge[0].x, wedge[0].y, wedge[1].x, wedge[1].y, shadow);
-				/* Draw a slider handle indicating current volume level. */
-				const int sw = ScaleGUITrad(slider_width);
-				byte volume = (widget == WID_M_MUSIC_VOL) ? _settings_client.music.music_vol : _settings_client.music.effect_vol;
-				if (_current_text_dir == TD_RTL) volume = 127 - volume;
-				const int x = r.left + (volume * (r.right - r.left - sw) / 127);
-				DrawFrameRect(x, r.top, x + sw, r.bottom, COLOUR_GREY, FR_NONE);
+			case WID_M_MUSIC_VOL:
+				DrawVolumeSliderWidget(r, _settings_client.music.music_vol);
+				break;
+
+			case WID_M_EFFECT_VOL:
+				DrawVolumeSliderWidget(r, _settings_client.music.effect_vol);
 				break;
-			}
 		}
 	}
 
@@ -801,18 +786,9 @@ struct MusicWindow : public Window {
 				break;
 
 			case WID_M_MUSIC_VOL: case WID_M_EFFECT_VOL: { // volume sliders
-				int x = pt.x - this->GetWidget<NWidgetBase>(widget)->pos_x;
-
-				byte *vol = (widget == WID_M_MUSIC_VOL) ? &_settings_client.music.music_vol : &_settings_client.music.effect_vol;
-
-				byte new_vol = Clamp(x * 127 / (int)this->GetWidget<NWidgetBase>(widget)->current_x, 0, 127);
-				if (_current_text_dir == TD_RTL) new_vol = 127 - new_vol;
-				/* Clamp to make sure min and max are properly settable */
-				if (new_vol > 124) new_vol = 127;
-				if (new_vol < 3) new_vol = 0;
-				if (new_vol != *vol) {
-					*vol = new_vol;
-					if (widget == WID_M_MUSIC_VOL) MusicDriver::GetInstance()->SetVolume(new_vol);
+				byte &vol = (widget == WID_M_MUSIC_VOL) ? _settings_client.music.music_vol : _settings_client.music.effect_vol;
+				if (ClickVolumeSliderWidget(this->GetWidget<NWidgetBase>(widget)->GetCurrentRect(), pt, vol)) {
+					if (widget == WID_M_MUSIC_VOL) MusicDriver::GetInstance()->SetVolume(vol);
 					this->SetDirty();
 				}
 
diff --git a/src/settings_gui.cpp b/src/settings_gui.cpp
index 68587c46a..513a3ef8f 100644
--- a/src/settings_gui.cpp
+++ b/src/settings_gui.cpp
@@ -21,6 +21,7 @@
 #include "string_func.h"
 #include "widgets/dropdown_type.h"
 #include "widgets/dropdown_func.h"
+#include "widgets/slider_func.h"
 #include "highscore.h"
 #include "base_media_base.h"
 #include "company_base.h"
diff --git a/src/widgets/CMakeLists.txt b/src/widgets/CMakeLists.txt
index 18ecd529e..5586870a3 100644
--- a/src/widgets/CMakeLists.txt
+++ b/src/widgets/CMakeLists.txt
@@ -44,6 +44,8 @@ add_files(
     screenshot_widget.h
     settings_widget.h
     sign_widget.h
+    slider.cpp
+    slider_func.h
     smallmap_widget.h
     station_widget.h
     statusbar_widget.h
diff --git a/src/widgets/slider.cpp b/src/widgets/slider.cpp
new file mode 100644
index 000000000..6d6d73288
--- /dev/null
+++ b/src/widgets/slider.cpp
@@ -0,0 +1,70 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file slider.cpp Implementation of the horizontal slider widget. */
+
+#include "../stdafx.h"
+#include "../window_gui.h"
+#include "../window_func.h"
+#include "../strings_func.h"
+#include "../zoom_func.h"
+#include "slider_func.h"
+
+#include "../safeguards.h"
+
+
+/**
+ * Draw a volume slider widget with know at given value
+ * @param r     Rectangle to draw the widget in
+ * @param value Value to put the slider at
+ */
+void DrawVolumeSliderWidget(Rect r, byte value)
+{
+	static const int slider_width = 3;
+
+	/* Draw a wedge indicating low to high volume level. */
+	const int ha = (r.bottom - r.top) / 5;
+	int wx1 = r.left, wx2 = r.right;
+	if (_current_text_dir == TD_RTL) std::swap(wx1, wx2);
+	const uint shadow = _colour_gradient[COLOUR_GREY][3];
+	const uint fill = _colour_gradient[COLOUR_GREY][6];
+	const uint light = _colour_gradient[COLOUR_GREY][7];
+	const std::vector<Point> wedge{ Point{wx1, r.bottom - ha}, Point{wx2, r.top + ha}, Point{wx2, r.bottom - ha} };
+	GfxFillPolygon(wedge, fill);
+	GfxDrawLine(wedge[0].x, wedge[0].y, wedge[2].x, wedge[2].y, light);
+	GfxDrawLine(wedge[1].x, wedge[1].y, wedge[2].x, wedge[2].y, _current_text_dir == TD_RTL ? shadow : light);
+	GfxDrawLine(wedge[0].x, wedge[0].y, wedge[1].x, wedge[1].y, shadow);
+
+	/* Draw a slider handle indicating current volume level. */
+	const int sw = ScaleGUITrad(slider_width);
+	if (_current_text_dir == TD_RTL) value = 127 - value;
+	const int x = r.left + (value * (r.right - r.left - sw) / 127);
+	DrawFrameRect(x, r.top, x + sw, r.bottom, COLOUR_GREY, FR_NONE);
+}
+
+/**
+ * Handle click on a volume slider widget to change the value
+ * @param r      Rectangle of the widget
+ * @param pt     Clicked point
+ * @param value[in,out] Volume value to modify
+ * @return       True if the volume setting was modified
+ */
+bool ClickVolumeSliderWidget(Rect r, Point pt, byte &value)
+{
+	byte new_vol = Clamp((pt.x - r.left) * 127 / (r.right - r.left), 0, 127);
+	if (_current_text_dir == TD_RTL) new_vol = 127 - new_vol;
+
+	/* Clamp to make sure min and max are properly settable */
+	if (new_vol > 124) new_vol = 127;
+	if (new_vol < 3) new_vol = 0;
+	if (new_vol != value) {
+		value = new_vol;
+		return true;
+	}
+
+	return false;
+}
diff --git a/src/widgets/slider_func.h b/src/widgets/slider_func.h
new file mode 100644
index 000000000..1aa1fa10c
--- /dev/null
+++ b/src/widgets/slider_func.h
@@ -0,0 +1,21 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file slider_type.h Types related to the horizontal slider widget. */
+
+#ifndef WIDGETS_SLIDER_TYPE_H
+#define WIDGETS_SLIDER_TYPE_H
+
+#include "../window_type.h"
+#include "../gfx_func.h"
+
+
+void DrawVolumeSliderWidget(Rect r, byte value);
+bool ClickVolumeSliderWidget(Rect r, Point pt, byte &value);
+
+
+#endif /* WIDGETS_SLIDER_TYPE_H */