Handle common aspect ratios

data/launcher.desktop.in

@@ -1,7 +1,7 @@
 [Desktop Entry]
 Name=Dippi
 GenericName=Display information calculator
-Comment=Calculate display info like DPI and aspect ratio
+Comment=Calculate display info like DPI
 Categories=Calculator;Utility;
 Exec=com.github.cassidyjames.dippi
 Icon=com.github.cassidyjames.dippi

data/metainfo.appdata.xml.in

@@ -83,6 +83,18 @@
     </screenshot>
   </screenshots>
   <releases>
+    <release version="4.1.1" date="2024-08-21">
+      <description>
+        <p>Lies! Deception!</p>
+        <ul>
+          <li>Better handle several common resolutions/aspect ratios</li>
+        </ul>
+      </description>
+      <issues>
+        <issue url="https://github.com/cassidyjames/dippi/issues/6">Common aspect ratios are dumb</issue>
+        <issue url="https://github.com/cassidyjames/dippi/issues/55">Unexpected ratio for 3440×1440</issue>
+      </issues>
+    </release>
     <release version="4.1.0" date="2024-08-20">
       <description>
         <p>Lighten up!</p>

meson.build

@@ -1,7 +1,7 @@
 project(
   'com.github.cassidyjames.dippi',
   'vala', 'c',
-  version: '4.1.0',
+  version: '4.1.1',
   meson_version: '>=1.3.2',
 )
 

src/App.vala

@@ -1,6 +1,6 @@
 /*
  * SPDX-License-Identifier: GPL-3.0-or-later
- * SPDX-FileCopyrightText: 2018–2023 Cassidy James Blaede <[email protected]>
+ * SPDX-FileCopyrightText: 2018–2024 Cassidy James Blaede <[email protected]>
  */
 
 public class Dippi.App : Adw.Application {

src/Config.vala.in

@@ -1,2 +1,7 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ * SPDX-FileCopyrightText: 2018–2024 Cassidy James Blaede <[email protected]>
+ */
+
 public const string APP_ID = @APP_ID@;
 public const string VERSION = @VERSION@;

src/MainWindow.vala

@@ -1,6 +1,6 @@
 /*
  * SPDX-License-Identifier: GPL-3.0-or-later
- * SPDX-FileCopyrightText: 2018–2023 Cassidy James Blaede <[email protected]>
+ * SPDX-FileCopyrightText: 2018–2024 Cassidy James Blaede <[email protected]>
  */
 
 public class Dippi.MainWindow : Adw.ApplicationWindow {
@@ -16,10 +16,7 @@ public class Dippi.MainWindow : Adw.ApplicationWindow {
     private const int EXTERNAL_UNCLEAR_RANGE = 20;
 
     private const double INCHES_INFER_EXTERNAL = 18;
-    private const int DPI_INFER_HIDPI = 192; // According to GNOME
-
-    private int aspect_width = DEFAULT_ASPECT_WIDTH;
-    private int aspect_height = DEFAULT_ASPECT_HEIGHT;
+    private const int DPI_INFER_HIDPI = 192; // According to GNOME and elementary
 
     private double inches = 0.0;
     private int width = 0;
@@ -38,7 +35,7 @@ public class Dippi.MainWindow : Adw.ApplicationWindow {
     private Gtk.Stack range_stack;
     private Utils.DisplayType display_type;
 
-    public MainWindow (Gtk.Application application) {
+    public MainWindow (Adw.Application application) {
         Object (
             application: application,
             resizable: false
@@ -98,6 +95,7 @@ public class Dippi.MainWindow : Adw.ApplicationWindow {
             pixel_size = 128
         };
 
+        ///TRANSLATORS: Label for the entry for the diagonal size of the display, e.g. 27-inches
         var diag_label = new Gtk.Label (_("Diagonal size:")) {
             halign = Gtk.Align.END
         };
@@ -110,6 +108,7 @@ public class Dippi.MainWindow : Adw.ApplicationWindow {
         var diag_entry_focus_controller = new Gtk.EventControllerFocus ();
         diag_entry.add_controller (diag_entry_focus_controller);
 
+        ///TRANSLATORS: Label for the entry for the pixel resolution of the display, e.g. 1920×1080
         var res_label = new Gtk.Label (_("Resolution:")) {
             halign = Gtk.Align.END
         };
@@ -130,13 +129,14 @@ public class Dippi.MainWindow : Adw.ApplicationWindow {
         var height_entry_focus_controller = new Gtk.EventControllerFocus ();
         height_entry.add_controller (height_entry_focus_controller);
 
-        var x_label = new Gtk.Label (_("×"));
-        var px_label = new Gtk.Label (_("px"));
+        var x_label = new Gtk.Label ("×");
+        var px_label = new Gtk.Label ("px");
 
         var inches_label = new Gtk.Label (_("inches")) {
             halign = Gtk.Align.START
         };
 
+        ///TRANSLATORS: Used to label the selection for type of display (e.g. laptop or desktop)
         var type_label = new Gtk.Label (_("Type:")) {
             halign = Gtk.Align.END
         };
@@ -192,6 +192,7 @@ public class Dippi.MainWindow : Adw.ApplicationWindow {
 
         link_button = new Gtk.LinkButton.with_label (
             "https://cassidyjames.com/dippi/",
+            ///TRANSLATORS: label for the button to open a web page to share the results of the calculation
             _("Share results…")
         ) {
             halign = Gtk.Align.END,
@@ -429,9 +430,7 @@ public class Dippi.MainWindow : Adw.ApplicationWindow {
 
     private void recalculate_aspect (int width, int height) {
         if (width > 0 && height > 0) {
-            aspect_width = width / Utils.greatest_common_divisor (width, height);
-            aspect_height = height / Utils.greatest_common_divisor (width, height);
-            aspect_result_label.label = (aspect_width).to_string () + _(":") + (aspect_height).to_string ();
+            aspect_result_label.label = Utils.common_ratio (width, height);
         } else {
             aspect_result_label.label = "";
         }

src/Utils.vala

@@ -1,6 +1,6 @@
 /*
  * SPDX-License-Identifier: GPL-3.0-or-later
- * SPDX-FileCopyrightText: 2018–2022 Cassidy James Blaede <[email protected]>
+ * SPDX-FileCopyrightText: 2018–2024 Cassidy James Blaede <[email protected]>
  */
 
 namespace Dippi.Utils {
@@ -11,9 +11,11 @@ namespace Dippi.Utils {
         public string to_string () {
             switch (this) {
                 case INTERNAL:
+                    ///TRANSLATORS: label for the button to select an internal/laptop display
                     return _("Laptop");
 
                 case EXTERNAL:
+                    ///TRANSLATORS: label for the button to select an external/desktop monitor
                     return _("Desktop");
 
                 default:
@@ -60,4 +62,94 @@ namespace Dippi.Utils {
             return greatest_common_divisor (a, b % a);
         }
     }
+
+    public string common_ratio (int width, int height) {
+        // We don't need every possible resolution/aspect ratio handled here, but
+        // https://en.wikipedia.org/wiki/List_of_computer_display_standards
+        // is a decent place to check. For now, this is just case-by-case for
+        // common resolutions and aspect ratios we've seen in the wild.
+        //
+        // We can also use this to catch "backwards" ratios, e.g. portrait
+        // displays (like on a smartphone).
+        //
+        // In general, put the true (or approximately true) ratio first, then put
+        // any other aspect ratio (like one used in marketing) in parenthesis.
+
+        int aspect_width = width / greatest_common_divisor (width, height);
+        int aspect_height = height / greatest_common_divisor (width, height);
+
+        string aspect_string = "%i:%i".printf (aspect_width, aspect_height);
+
+        switch (aspect_string) {
+            case "1:2":
+            case "2:1":
+                return "2:1 (18:9)";
+
+            case "2:3":
+                return "3:2";
+
+            case "3:4":
+                return "4:3";
+
+            // The funkiest
+            case "64:45":
+            case "45:64":
+                return "2:√2";
+
+            case "5:8":
+            case "8:5":
+                return "8:5 (16:10)";
+
+            // Some smartphones
+            case "18:37":
+            case "37:18":
+                return "37:18 (18.5:9)";
+
+            // Pretty much just iPhone absurdity
+            case "422:195":
+            case "195:422":
+            case "466:215":
+            case "215:466":
+            case "284:131":
+            case "131:284":
+            case "463:214":
+            case "214:463":
+            case "448:207":
+            case "207:448":
+            case "812:375":
+            case "375:812":
+            case "6:13":
+            case "13:6":
+                return "13:6 (19.5:9)";
+
+            case "84:187":
+            case "187:84":
+            case "101:45":
+            case "45:101":
+                return "20:9";
+
+            case "3:7":
+            case "7:3":
+            // e.g. 3440×1440
+            case "43:18":
+                return "7:3 (21:9)";
+
+            // 1360×768
+            case "48:85":
+            case "85:48":
+            // 1366×768
+            case "384:683":
+            case "683:384":
+            // iPhone 6–8
+            case "667:375":
+            case "375:667":
+            // iPhone 5
+            case "71:40":
+            case "40:71":
+                return "16:9";
+
+            default:
+                return aspect_string;
+        }
+    }
 }