From 7dbd9402c1f6c1d0a28c1e2f6af233ff3837ed31 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Tue, 31 Oct 2017 21:10:29 -0400
Subject: [PATCH] Add Jtk_SetWindowIcon()

---
 src/gui/Window.cc         | 27 ++++++++++++++++++---------
 src/gui/Window.h          |  2 --
 src/gui/jtk/Jtk_window.cc | 38 +++++++++++++++++++++++++++++++++++++-
 src/gui/jtk/Jtk_window.h  |  2 ++
 4 files changed, 57 insertions(+), 12 deletions(-)

diff --git a/src/gui/Window.cc b/src/gui/Window.cc
index dba2fef..ced9dc1 100644
--- a/src/gui/Window.cc
+++ b/src/gui/Window.cc
@@ -52,16 +52,27 @@ static bool Initialize_OpenGL()
     return true;
 }
 
-#if 0
 void Window::set_window_icon()
 {
-    SDL_Surface * surface = SDL_CreateRGBSurfaceFrom((void *)jes_icon_32x32, 32, 32, 24, 32 * 3, 0xFF0000u, 0xFF00u, 0xFFu, 0u);
-
-    SDL_SetWindowIcon(m_window, surface);
-
-    SDL_FreeSurface(surface);
+    uint8_t * icon_bgra = (uint8_t *)malloc(32u * 32u * 4u);
+    uint8_t * out_icon = icon_bgra;
+    const uint8_t * in_icon = jes_icon_32x32;
+    for (int row = 0; row < 32; row++)
+    {
+        for (int col = 0; col < 32; col++)
+        {
+            uint8_t r = *in_icon++;
+            uint8_t g = *in_icon++;
+            uint8_t b = *in_icon++;
+            *out_icon++ = b;
+            *out_icon++ = g;
+            *out_icon++ = r;
+            *out_icon++ = 0xFFu;
+        }
+    }
+    Jtk_SetWindowIcon(m_window, icon_bgra, 32, 32);
+    free(icon_bgra);
 }
-#endif
 
 /**
  * Create a Window.
@@ -85,9 +96,7 @@ bool Window::create(std::shared_ptr<Buffer> buffer)
     }
     Jtk_SetWindowTitle(m_window, "jes");
 
-#if 0
     set_window_icon();
-#endif
 
     if (!Initialize_OpenGL())
     {
diff --git a/src/gui/Window.h b/src/gui/Window.h
index d470e42..cbfb660 100644
--- a/src/gui/Window.h
+++ b/src/gui/Window.h
@@ -46,9 +46,7 @@ protected:
     void handle_event(Jtk_Event & event);
     void handle_keypress(uint32_t keyval);
     void change_focus(std::shared_ptr<BufferPane> buffer_pane);
-#if 0
     void set_window_icon();
-#endif
     void handle_command(const EncodedString & command);
 
     void command_write_file(const CommandParser & cp);
diff --git a/src/gui/jtk/Jtk_window.cc b/src/gui/jtk/Jtk_window.cc
index e538789..e7e43b3 100644
--- a/src/gui/jtk/Jtk_window.cc
+++ b/src/gui/jtk/Jtk_window.cc
@@ -1,4 +1,3 @@
-
 #include "Jtk.h"
 
 #ifdef JTK_X
@@ -7,6 +6,7 @@
 #include "Jtk_internal.h"
 #include <stdio.h>
 #include <X11/Xatom.h>
+#include <cstring>
 
 static Bool WaitForNotify(Display * display, XEvent * event, XPointer arg)
 {
@@ -56,4 +56,40 @@ void Jtk_SetWindowTitle(void * window, const char * title)
     }
 }
 
+/**
+ * Set the window icon.
+ *
+ * @param window
+ *   The window to operate on.
+ * @param data
+ *   The format of data must be 32 bits per pixel in BGRA format (e.g. data[0]
+ *   is blue value, data[3] is alpha value of first pixel).
+ * @param width
+ *   Icon width.
+ * @param height
+ *   Icon height.
+ */
+void Jtk_SetWindowIcon(void * window, const uint8_t * data,
+        size_t width, size_t height)
+{
+    Atom net_wm_icon_atom = XInternAtom(g_display, "_NET_WM_ICON", False);
+    size_t property_size = (2u + width * height) * sizeof(long);
+    unsigned long * property_data = (unsigned long *)malloc(property_size);
+    property_data[0] = width;
+    property_data[1] = height;
+    unsigned long * dest = &property_data[2];
+    const uint32_t * src = (const uint32_t *)data;
+    for (size_t row = 0u; row < height; row++)
+    {
+        for (size_t col = 0u; col < width; col++)
+        {
+            *dest++ = *src++;
+        }
+    }
+    XChangeProperty(g_display, (Window)window, net_wm_icon_atom, XA_CARDINAL,
+            32, PropModeReplace, (uint8_t *)property_data, property_size);
+    XFlush(g_display);
+    free(property_data);
+}
+
 #endif
diff --git a/src/gui/jtk/Jtk_window.h b/src/gui/jtk/Jtk_window.h
index 720c036..a0dc373 100644
--- a/src/gui/jtk/Jtk_window.h
+++ b/src/gui/jtk/Jtk_window.h
@@ -5,5 +5,7 @@ void * Jtk_CreateWindow();
 void Jtk_SwapBuffers(void * window);
 void Jtk_CloseWindow(void * window);
 void Jtk_SetWindowTitle(void * window, const char * title);
+void Jtk_SetWindowIcon(void * window, const uint8_t * data,
+        size_t width, size_t height);
 
 #endif