console: Use icu to provide proper UTF-8 editing

12 files changed, 131 insertions, 12 deletions

diff --git a/.builds/archlinux.yml b/.builds/archlinux.yml
index 27db21f..c60bbf7 100644
--- a/.builds/archlinux.yml
+++ b/.builds/archlinux.yml
@@ -3,6 +3,7 @@ packages:
   - clang
   - cmocka
   - freeimage
+  - icu
   - libjpeg-turbo
   - libpng
   - librsvg
diff --git a/.builds/debian.yml b/.builds/debian.yml
index d11ceef..81e2959 100644
--- a/.builds/debian.yml
+++ b/.builds/debian.yml
@@ -5,6 +5,7 @@ packages:
   - libegl1-mesa-dev
   - libfreeimage-dev
   - libglu-dev
+  - libicu-dev
   - libpango1.0-dev
   - libpng-dev
   - librsvg2-dev
diff --git a/.builds/fedora.yml b/.builds/fedora.yml
index 4bcec48..e641dde 100644
--- a/.builds/fedora.yml
+++ b/.builds/fedora.yml
@@ -4,6 +4,7 @@ packages:
   - freeimage-devel
   - libX11-devel
   - libcmocka-devel
+  - libicu-devel
   - libpng-devel
   - librsvg2-devel
   - libtiff-devel
diff --git a/.builds/freebsd.yml b/.builds/freebsd.yml
index 449b84d..98b62e7 100644
--- a/.builds/freebsd.yml
+++ b/.builds/freebsd.yml
@@ -1,6 +1,7 @@
 image: freebsd/latest
 packages:
   - devel/gmake
+  - devel/icu
   - devel/pkgconf
   - graphics/freeimage
   - graphics/libGLU
diff --git a/.builds/ubuntu.yml b/.builds/ubuntu.yml
index 3e8b080..0477de9 100644
--- a/.builds/ubuntu.yml
+++ b/.builds/ubuntu.yml
@@ -5,6 +5,7 @@ packages:
   - libegl1-mesa-dev
   - libfreeimage-dev
   - libglu-dev
+  - libicu-dev
   - libpango1.0-dev
   - libpng-dev
   - librsvg2-dev
diff --git a/Makefile b/Makefile
index d2a8b5a..2f0ff1d 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ INSTALL_SCRIPT ?= install -m 0755
 
 override CFLAGS += -std=c99 -W -Wall -Wpedantic -Wextra $(shell pkg-config --cflags pangocairo)
 override CPPFLAGS += -D_XOPEN_SOURCE=700
-override LIBS := -lGL -lpthread -lxkbcommon $(shell pkg-config --libs pangocairo)
+override LIBS := -lGL -lpthread -lxkbcommon $(shell pkg-config --libs pangocairo) $(shell pkg-config --libs icu-io)
 
 BUILDDIR ?= build
 TARGET_WAYLAND = $(BUILDDIR)/imv-wayland
diff --git a/README.md b/README.md
index bb4e5d3..9e8008e 100644
--- a/README.md
+++ b/README.md
@@ -120,6 +120,7 @@ Installation
 | pthreads       |          | Required.                                      |
 | xkbcommon      |          | Required.                                      |
 | pangocairo     |          | Required.                                      |
+| icu            |          | Required.                                      |
 | X11            |          | Optional. Required for X11 support.            |
 | GLU            |          | Optional. Required for X11 support.            |
 | xcb            |          | Optional. Required for X11 support.            |
diff --git a/src/canvas.c b/src/canvas.c
index 4a00dbc..eaec538 100644
--- a/src/canvas.c
+++ b/src/canvas.c
@@ -127,7 +127,7 @@ void imv_canvas_font(struct imv_canvas *canvas, const char *name, int size)
   pango_font_description_set_absolute_size(canvas->font, size * PANGO_SCALE);
 }
 
-void imv_canvas_printf(struct imv_canvas *canvas, int x, int y, const char *fmt, ...)
+int imv_canvas_printf(struct imv_canvas *canvas, int x, int y, const char *fmt, ...)
 {
   char line[1024];
   va_list args;
@@ -140,9 +140,14 @@ void imv_canvas_printf(struct imv_canvas *canvas, int x, int y, const char *fmt,
 
   cairo_move_to(canvas->cairo, x, y);
   pango_cairo_show_layout(canvas->cairo, layout);
+
+  PangoRectangle extents;
+  pango_layout_get_pixel_extents(layout, NULL, &extents);
+
   g_object_unref(layout);
 
   va_end(args);
+  return extents.width;
 }
 
 void imv_canvas_draw(struct imv_canvas *canvas)
diff --git a/src/canvas.h b/src/canvas.h
index 4f520fe..03425d9 100644
--- a/src/canvas.h
+++ b/src/canvas.h
@@ -37,8 +37,8 @@ void imv_canvas_fill_checkers(struct imv_canvas *canvas, int size);
 /* Select the font to draw text with */
 void imv_canvas_font(struct imv_canvas *canvas, const char *name, int size);
 
-/* Draw some text on the canvas */
-void imv_canvas_printf(struct imv_canvas *canvas, int x, int y, const char *fmt, ...);
+/* Draw some text on the canvas, returns the width used in pixels */
+int imv_canvas_printf(struct imv_canvas *canvas, int x, int y, const char *fmt, ...);
 
 /* Blit the canvas to the current OpenGL framebuffer */
 void imv_canvas_draw(struct imv_canvas *canvas);
diff --git a/src/console.c b/src/console.c
index 92e578d..01b7925 100644
--- a/src/console.c
+++ b/src/console.c
@@ -1,15 +1,65 @@
 #include "console.h"
 
+#include <assert.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unicode/utext.h>
+#include <unicode/ubrk.h>
 
 struct imv_console {
   char *buffer;
   size_t buffer_len;
+  size_t cursor;
+
   imv_console_callback callback;
   void *callback_data;
 };
 
+/* Iterates forwards over characters in a UTF-8 string */
+static size_t next_char(char *buffer, size_t position)
+{
+  size_t result = position;
+  UErrorCode status = U_ZERO_ERROR;
+  UText *ut = utext_openUTF8(NULL, buffer, -1, &status);
+
+  UBreakIterator *it = ubrk_open(UBRK_CHARACTER, NULL, NULL, 0, &status);
+  ubrk_setUText(it, ut, &status);
+
+  int boundary = ubrk_following(it, (int)position);
+  if (boundary != UBRK_DONE) {
+    result = (size_t)boundary;
+  }
+
+  ubrk_close(it);
+
+  utext_close(ut);
+  assert(U_SUCCESS(status));
+  return result;
+}
+
+/* Iterates backwards over characters in a UTF-8 string */
+static size_t prev_char(char *buffer, size_t position)
+{
+  size_t result = position;
+  UErrorCode status = U_ZERO_ERROR;
+  UText *ut = utext_openUTF8(NULL, buffer, -1, &status);
+
+  UBreakIterator *it = ubrk_open(UBRK_CHARACTER, NULL, NULL, 0, &status);
+  ubrk_setUText(it, ut, &status);
+
+  int boundary = ubrk_preceding(it, (int)position);
+  if (boundary != UBRK_DONE) {
+    result = (size_t)boundary;
+  }
+
+  ubrk_close(it);
+
+  utext_close(ut);
+  assert(U_SUCCESS(status));
+  return result;
+}
+
+
 struct imv_console *imv_console_create(void)
 {
   struct imv_console *console = calloc(1, sizeof *console);
@@ -45,6 +95,7 @@ void imv_console_activate(struct imv_console *console)
   }
 
   console->buffer = calloc(1, console->buffer_len);
+  console->cursor = 0;
 }
 
 void imv_console_input(struct imv_console *console, const char *text)
@@ -53,7 +104,21 @@ void imv_console_input(struct imv_console *console, const char *text)
     return;
   }
 
-  strncat(console->buffer, text, console->buffer_len - 1);
+  /* Increase buffer size if needed */
+  if (strlen(text) + strlen(console->buffer) + 1 > console->buffer_len) {
+    console->buffer_len *= 2;
+    console->buffer = realloc(console->buffer, console->buffer_len);
+    assert(console->buffer);
+  }
+
+  /* memmove over everything after the cursor right then copy in the new bytes */
+  size_t to_insert = strlen(text);
+  size_t old_cursor = console->cursor;
+  size_t new_cursor = console->cursor + to_insert;
+  size_t to_shift = strlen(console->buffer) - old_cursor;
+  memmove(&console->buffer[new_cursor], &console->buffer[old_cursor], to_shift);
+  memcpy(&console->buffer[old_cursor], text, to_insert);
+  console->cursor = new_cursor;
 }
 
 bool imv_console_key(struct imv_console *console, const char *key)
@@ -77,11 +142,33 @@ bool imv_console_key(struct imv_console *console, const char *key)
     return true;
   }
 
+  if (!strcmp("Left", key) || !strcmp("Ctrl+b", key)) {
+    console->cursor = prev_char(console->buffer, console->cursor);
+    return true;
+  }
+
+  if (!strcmp("Right", key) || !strcmp("Ctrl+f", key)) {
+    console->cursor = next_char(console->buffer, console->cursor);
+    return true;
+  }
+
+  if (!strcmp("Ctrl+a", key)) {
+    console->cursor = 0;
+    return true;
+  }
+
+  if (!strcmp("Ctrl+e", key)) {
+    console->cursor = strlen(console->buffer);
+    return true;
+  }
+
   if (!strcmp("BackSpace", key)) {
-    const size_t len = strlen(console->buffer);
-    if (len > 0) {
-      console->buffer[len - 1] = '\0';
-    }
+    /* memmove everything after the cursor left */
+    size_t new_cursor = prev_char(console->buffer, console->cursor);
+    size_t old_cursor = console->cursor;
+    size_t to_shift = strlen(console->buffer) - new_cursor;
+    memmove(&console->buffer[new_cursor], &console->buffer[old_cursor], to_shift);
+    console->cursor = new_cursor;
     return true;
   }
 
@@ -93,6 +180,11 @@ const char *imv_console_prompt(struct imv_console *console)
   return console->buffer;
 }
 
+size_t imv_console_prompt_cursor(struct imv_console *console)
+{
+  return console->cursor;
+}
+
 const char *imv_console_backlog(struct imv_console *console)
 {
   (void)console;
diff --git a/src/console.h b/src/console.h
index 22cf9b6..d8d270d 100644
--- a/src/console.h
+++ b/src/console.h
@@ -2,6 +2,7 @@
 #define IMV_CONSOLE
 
 #include <stdbool.h>
+#include <unistd.h>
 
 struct imv_console;
 
@@ -33,6 +34,9 @@ bool imv_console_key(struct imv_console *console, const char *key);
 /* What is the console prompt's current text? */
 const char *imv_console_prompt(struct imv_console *console);
 
+/* What is the console prompt's current cursor position? (bytes into UTF-8 string) */
+size_t imv_console_prompt_cursor(struct imv_console *console);
+
 /* What is the output history of the console? */
 const char *imv_console_backlog(struct imv_console *console);
 
diff --git a/src/imv.c b/src/imv.c
index a612bb2..4231fd4 100644
--- a/src/imv.c
+++ b/src/imv.c
@@ -377,7 +377,7 @@ static void key_handler(struct imv *imv, const struct imv_event *event)
 {
   if (imv_console_is_active(imv->console)) {
 
-    if (imv_console_key(imv->console, event->data.keyboard.keyname)) {
+    if (imv_console_key(imv->console, event->data.keyboard.description)) {
       imv->need_redraw = true;
       return;
     }
@@ -1209,8 +1209,20 @@ static void render_window(struct imv *imv)
     imv_canvas_fill_rectangle(imv->canvas, 0, wh - height - bottom_offset,
         ww, height + bottom_offset);
     imv_canvas_color(imv->canvas, 1, 1, 1, 1);
-    imv_canvas_printf(imv->canvas, 0, wh - height - bottom_offset,
-        ":%s\u2588", imv_console_prompt(imv->console));
+
+    int x = 0;
+    /* draw pre-cursor text */
+    x += imv_canvas_printf(imv->canvas, x, wh - height - bottom_offset,
+        ":%.*s",
+        imv_console_prompt_cursor(imv->console),
+        imv_console_prompt(imv->console));
+    /* draw the cursor */
+    imv_canvas_color(imv->canvas, 1, 1, 1, 0.5);
+    imv_canvas_printf(imv->canvas, x, wh - height - bottom_offset, "\u2588");
+    /* any any remaining text on top of the cursor */
+    imv_canvas_color(imv->canvas, 1, 1, 1, 1);
+    imv_canvas_printf(imv->canvas, x, wh - height - bottom_offset, "%s",
+        imv_console_prompt(imv->console) + imv_console_prompt_cursor(imv->console));
   }
 
   imv_canvas_draw(imv->canvas);