implemented <ER> command for reading a file into the current buffer

* This command exists in Video TECO.
  In Video TECO it also supports reading multiple files with a glob pattern -- we do not support that
  as I am not convinced of its usefulness.
* teco_view_load() has been extended, so it can read into dot without
  discarding the existing document.

6 files changed, 89 insertions, 27 deletions

diff --git a/src/core-commands.c b/src/core-commands.c
index 0ff2b81..8e31ae3 100644
--- a/src/core-commands.c
+++ b/src/core-commands.c
@@ -2686,6 +2686,8 @@ teco_state_ecommand_input(teco_machine_main_t *ctx, gunichar chr, GError **error
 		          .modifier_at = TRUE, .modifier_colon = 1},
 		['W']  = {&teco_state_save_file,
 		          .modifier_at = TRUE},
+		['R']  = {&teco_state_read_file,
+		          .modifier_at = TRUE},
 
 		/*
 		 * Commands
diff --git a/src/qreg.c b/src/qreg.c
index 91f0deb..f08be17 100644
--- a/src/qreg.c
+++ b/src/qreg.c
@@ -337,7 +337,7 @@ teco_qreg_plain_load(teco_qreg_t *qreg, const gchar *filename, GError **error)
 	 * So if loading fails, teco_qreg_current will be
 	 * made the current document again.
 	 */
-	if (!teco_view_load(teco_qreg_view, filename, error))
+	if (!teco_view_load(teco_qreg_view, filename, TRUE, error))
 		return FALSE;
 
 	if (teco_qreg_current)
diff --git a/src/ring.c b/src/ring.c
index 1c9a2cd..afda650 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -77,7 +77,7 @@ teco_buffer_undo_edit(teco_buffer_t *ctx)
 static gboolean
 teco_buffer_load(teco_buffer_t *ctx, const gchar *filename, GError **error)
 {
-	if (!teco_view_load(ctx->view, filename, error))
+	if (!teco_view_load(ctx->view, filename, TRUE, error))
 		return FALSE;
 
 #if 0		/* NOTE: currently buffer cannot be dirty */
@@ -595,6 +595,40 @@ teco_state_save_file_done(teco_machine_main_t *ctx, const teco_string_t *str, GE
  */
 TECO_DEFINE_STATE_EXPECTFILE(teco_state_save_file);
 
+static teco_state_t *
+teco_state_read_file_done(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
+{
+	if (ctx->flags.mode > TECO_MODE_NORMAL)
+		return &teco_state_start;
+
+	sptr_t pos = teco_interface_ssm(SCI_GETCURRENTPOS, 0, 0);
+
+	g_autofree gchar *filename = teco_file_expand_path(str->data);
+	/* FIXME: Add wrapper to interface.h? */
+	if (!teco_view_load(teco_interface_current_view, filename, FALSE, error))
+		return NULL;
+
+	if (teco_interface_ssm(SCI_GETCURRENTPOS, 0, 0) != pos) {
+		teco_ring_dirtify();
+
+		if (teco_current_doc_must_undo())
+			undo__teco_interface_ssm(SCI_UNDO, 0, 0);
+	}
+
+	return &teco_state_start;
+}
+
+/*$ ER read
+ * ER<file>$ -- Read and insert file into current buffer
+ *
+ * Reads and inserts the given <file> into the current buffer or Q-Register at dot.
+ * Dot is left immediately after the given file.
+ */
+/*
+ * NOTE: Video TECO allows glob patterns as an argument.
+ */
+TECO_DEFINE_STATE_EXPECTFILE(teco_state_read_file);
+
 /*$ EF close
  * [n]EF -- Remove buffer from ring
  * -EF
diff --git a/src/ring.h b/src/ring.h
index b75846a..6114839 100644
--- a/src/ring.h
+++ b/src/ring.h
@@ -99,6 +99,7 @@ void teco_ring_cleanup(void);
 
 TECO_DECLARE_STATE(teco_state_edit_file);
 TECO_DECLARE_STATE(teco_state_save_file);
+TECO_DECLARE_STATE(teco_state_read_file);
 
 void teco_state_ecommand_close(teco_machine_main_t *ctx, GError **error);
 
diff --git a/src/view.c b/src/view.c
index e21d53a..d08728d 100644
--- a/src/view.c
+++ b/src/view.c
@@ -198,16 +198,22 @@ teco_view_set_representations(teco_view_t *ctx)
  *
  * @param ctx The view to load.
  * @param channel Channel to read from.
+ * @param clear Whether to completely replace document
+ *   (leaving dot at the beginning of the document) or insert at dot
+ *   (leaving dot at the end of the insertion).
  * @param error A GError.
  * @return FALSE in case of a GError.
  *
  * @memberof teco_view_t
  */
 gboolean
-teco_view_load_from_channel(teco_view_t *ctx, GIOChannel *channel, GError **error)
+teco_view_load_from_channel(teco_view_t *ctx, GIOChannel *channel,
+                            gboolean clear, GError **error)
 {
 	gboolean ret = TRUE;
 
+	unsigned int message = SCI_ADDTEXT;
+
 	g_auto(teco_eol_reader_t) reader;
 	teco_eol_reader_init_gio(&reader, channel);
 
@@ -225,22 +231,27 @@ teco_view_load_from_channel(teco_view_t *ctx, GIOChannel *channel, GError **erro
 		                   SC_LINECHARACTERINDEX_UTF32, 0);
 
 	teco_view_ssm(ctx, SCI_BEGINUNDOACTION, 0, 0);
-	teco_view_ssm(ctx, SCI_CLEARALL, 0, 0);
+	if (clear) {
+		teco_view_ssm(ctx, SCI_CLEARALL, 0, 0);
 
-	/*
-	 * Preallocate memory based on the file size.
-	 * May waste a few bytes if file contains DOS EOLs
-	 * and EOL translation is enabled, but is faster.
-	 * NOTE: g_io_channel_unix_get_fd() should report the correct fd
-	 * on Windows, too.
-	 */
-	struct stat stat_buf = {.st_size = 0};
-	if (!fstat(g_io_channel_unix_get_fd(channel), &stat_buf) &&
-	    stat_buf.st_size > 0) {
-		ret = teco_memory_check(stat_buf.st_size, error);
-		if (!ret)
-			goto cleanup;
-		teco_view_ssm(ctx, SCI_ALLOCATE, stat_buf.st_size, 0);
+		/*
+		 * Preallocate memory based on the file size.
+		 * May waste a few bytes if file contains DOS EOLs
+		 * and EOL translation is enabled, but is faster.
+		 * NOTE: g_io_channel_unix_get_fd() should report the correct fd
+		 * on Windows, too.
+		 */
+		struct stat stat_buf = {.st_size = 0};
+		if (!fstat(g_io_channel_unix_get_fd(channel), &stat_buf) &&
+		    stat_buf.st_size > 0) {
+			ret = teco_memory_check(stat_buf.st_size, error);
+			if (!ret)
+				goto cleanup;
+			teco_view_ssm(ctx, SCI_ALLOCATE, stat_buf.st_size, 0);
+		}
+
+		/* keep dot at beginning of document */
+		message = SCI_APPENDTEXT;
 	}
 
 	for (;;) {
@@ -258,7 +269,7 @@ teco_view_load_from_channel(teco_view_t *ctx, GIOChannel *channel, GError **erro
 		if (rc == G_IO_STATUS_EOF)
 			break;
 
-		teco_view_ssm(ctx, SCI_APPENDTEXT, str.len, (sptr_t)str.data);
+		teco_view_ssm(ctx, message, str.len, (sptr_t)str.data);
 
 		/*
 		 * Even if we checked initially, knowing the file size,
@@ -285,7 +296,7 @@ teco_view_load_from_channel(teco_view_t *ctx, GIOChannel *channel, GError **erro
 	 * If it is enabled but the stream does not contain any
 	 * EOL characters, the platform default is still assumed.
 	 */
-	if (reader.eol_style >= 0)
+	if (clear && reader.eol_style >= 0)
 		teco_view_ssm(ctx, SCI_SETEOLMODE, reader.eol_style, 0);
 
 	if (reader.eol_style_inconsistent)
@@ -303,12 +314,21 @@ cleanup:
 }
 
 /**
- * Load view's document from file.
+ * Load file into view's document.
+ * 
+ * @param ctx The view to load.
+ * @param filename File name to read
+ * @param clear Whether to completely replace document
+ *   (leaving dot at the beginning of the document) or insert at dot
+ *   (leaving dot at the end of the insertion).
+ * @param error A GError.
+ * @return FALSE in case of a GError.
  *
  * @memberof teco_view_t
  */
 gboolean
-teco_view_load_from_file(teco_view_t *ctx, const gchar *filename, GError **error)
+teco_view_load_from_file(teco_view_t *ctx, const gchar *filename,
+                         gboolean clear, GError **error)
 {
 	g_autoptr(GIOChannel) channel = g_io_channel_new_file(filename, "r", error);
 	if (!channel)
@@ -322,7 +342,7 @@ teco_view_load_from_file(teco_view_t *ctx, const gchar *filename, GError **error
 	g_io_channel_set_encoding(channel, NULL, NULL);
 	g_io_channel_set_buffered(channel, FALSE);
 
-	if (!teco_view_load_from_channel(ctx, channel, error)) {
+	if (!teco_view_load_from_channel(ctx, channel, clear, error)) {
 		g_prefix_error(error, "Error reading file \"%s\": ", filename);
 		return FALSE;
 	}
diff --git a/src/view.h b/src/view.h
index 7776e5b..4e4b85e 100644
--- a/src/view.h
+++ b/src/view.h
@@ -52,13 +52,17 @@ teco_view_set_scintilla_undo(teco_view_t *ctx, gboolean state)
 	teco_view_ssm(ctx, SCI_SETUNDOCOLLECTION, state, 0);
 }
 
-gboolean teco_view_load_from_channel(teco_view_t *ctx, GIOChannel *channel, GError **error);
-gboolean teco_view_load_from_file(teco_view_t *ctx, const gchar *filename, GError **error);
+gboolean teco_view_load_from_channel(teco_view_t *ctx, GIOChannel *channel,
+                                     gboolean clear, GError **error);
+gboolean teco_view_load_from_file(teco_view_t *ctx, const gchar *filename,
+                                  gboolean clear, GError **error);
 
 /** @memberof teco_view_t */
-#define teco_view_load(CTX, FROM, ERROR) \
+#define teco_view_load(CTX, FROM, CLEAR, ERROR) \
 	(_Generic((FROM), GIOChannel *  : teco_view_load_from_channel, \
-	                  const gchar * : teco_view_load_from_file)((CTX), (FROM), (ERROR)))
+	                  gchar *       : teco_view_load_from_file, \
+	                  const gchar * : teco_view_load_from_file)((CTX), (FROM), \
+	                                                            (CLEAR), (ERROR)))
 
 gboolean teco_view_save_to_channel(teco_view_t *ctx, GIOChannel *channel, GError **error);
 gboolean teco_view_save_to_file(teco_view_t *ctx, const gchar *filename, GError **error);
@@ -66,6 +70,7 @@ gboolean teco_view_save_to_file(teco_view_t *ctx, const gchar *filename, GError
 /** @memberof teco_view_t */
 #define teco_view_save(CTX, TO, ERROR) \
 	(_Generic((TO), GIOChannel *  : teco_view_save_to_channel, \
+	                gchar *       : teco_view_save_to_file, \
 	                const gchar * : teco_view_save_to_file)((CTX), (TO), (ERROR)))
 
 /** @pure @memberof teco_view_t */