Added history and tab-completion based on the history contents. Fixed

potential segmentation fault if key symbol translation fails.


git-svn-id: https://samskivert.googlecode.com/svn/trunk@650 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/lookuplet/src/Makefile.am

@@ -1,5 +1,5 @@
 #
-# $Id: Makefile.am,v 1.4 2001/08/18 02:34:06 mdb Exp $
+# $Id: Makefile.am,v 1.5 2002/03/14 16:45:26 shaper Exp $
 
 bin_PROGRAMS = lookuplet
 
@@ -9,7 +9,8 @@ lookuplet_SOURCES = \
 	querybox.c \
 	preferences.c \
 	binding.c \
-	keysym-util.c
+	keysym-util.c \
+	history.c
 
 INCLUDES = 						\
 	-I.						\

projects/lookuplet/src/c/history.c

@@ -0,0 +1,118 @@
+/**
+ * $Id: history.c,v 1.1 2002/03/14 16:45:26 shaper Exp $
+ * 
+ * lookuplet - a utility for quickly looking up information
+ * Copyright (C) 2001 Michael Bayne
+ * 
+ * This program 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; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <gnome.h>
+
+#include "history.h"
+
+/* the array of historical entries */
+static gchar** _history;
+
+/* the last entry index retrieved */
+static int _ridx = 0;
+
+/* the insertion index for new history items */
+static int _iidx = 0;
+
+/* the number of entries saved in the text entry history */ 
+#define HISTORY_COUNT (10)
+
+void
+lk_init_history (void)
+{
+    /* allocate and initialize the array of history entries */
+    size_t size = sizeof(gchar*) * HISTORY_COUNT;
+    _history = g_malloc(size);
+    memset(_history, (int)NULL, size);
+}
+
+const gchar*
+lk_get_history (gboolean next)
+{
+    int actidx;
+
+    /* make sure the array is available */
+    if (_history == NULL) {
+        return NULL;
+    }
+
+    /* determine the sought-after index */
+    actidx = _ridx + ((next) ? -1 : 1);
+
+    /* make sure the index is valid and an entry exists */
+    if (actidx < 0 || actidx >= HISTORY_COUNT || _history[actidx] == NULL) {
+        return NULL;
+    }
+
+    /* update the retrieved index */
+    _ridx = actidx;
+
+    return _history[actidx];
+}
+
+const gchar*
+lk_get_history_expand (const gchar* entry)
+{
+    int i, len;
+
+    if (_history == NULL || entry == NULL) {
+        return NULL;
+    }
+
+    len = strlen(entry);
+    for (i = _iidx; i >= 0; i--) {
+        gchar* str = _history[i];
+        if (str != NULL && !g_strncasecmp(str, entry, len)) {
+            /* update the retrieved index for potential subsequent retrievals */
+            _ridx = i;
+            return str;
+        }
+    }
+
+    return NULL;
+}
+
+void
+lk_add_history (const gchar* entry)
+{
+    /* make sure the array is available and the entry is valid */
+    if (_history == NULL || entry == NULL) {
+        return;
+    }
+
+    /* if there's no space remaining, shift off the oldest entry */
+    if (_iidx == HISTORY_COUNT - 1 && _history[_iidx] != NULL) {
+        g_free(_history[0]);
+        memmove(_history, _history + 1, sizeof(gchar*) * (HISTORY_COUNT - 1));
+        _history[_iidx] = NULL;
+    }
+
+    /* remember the new entry */
+    _history[_iidx] = g_strdup(entry);
+
+    /* increment the insertion and retrieved index */
+    if (_iidx < HISTORY_COUNT - 1) {
+        _iidx++;
+        _ridx = _iidx;
+    } else {
+        _ridx = HISTORY_COUNT;
+    }
+}

projects/lookuplet/src/c/history.h

@@ -0,0 +1,59 @@
+/**
+ * $Id: history.h,v 1.1 2002/03/14 16:45:26 shaper Exp $
+ * 
+ * lookuplet - a utility for quickly looking up information
+ * Copyright (C) 2001 Michael Bayne
+ * 
+ * This program 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; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _HISTORY_H_
+#define _HISTORY_H_
+
+#include <glib.h>
+
+/**
+ * Initializes the history storage.
+ */
+void
+lk_init_history (void);
+
+/**
+ * Returns the next history entry if next is true, else returns the
+ * previous history entry.
+ */
+const gchar*
+lk_get_history (gboolean next);
+
+/**
+ * Returns the most recent history entry that matches the specified
+ * partial entry text, or NULL if there are no matches.  String
+ * comparisons are case-insensitive as this is intended for use in
+ * effecting auto-completion of sloppily-inputted partial entries.  If a
+ * matching entry is found, the current history item index is set to point
+ * to that entry such that subsequent history entry retrievals will
+ * automagically pick up from that point.
+ */
+const gchar*
+lk_get_history_expand (const gchar* entry);
+
+/**
+ * Adds an entry to the history and resets the current history item index
+ * to point to the new entry.
+ */
+void
+lk_add_history (const gchar* entry);
+
+#endif /* _HISTORY_H_ */

projects/lookuplet/src/c/lookuplet.c

@@ -1,5 +1,5 @@
 /**
- * $Id: lookuplet.c,v 1.6 2001/08/18 02:34:06 mdb Exp $
+ * $Id: lookuplet.c,v 1.7 2002/03/14 16:45:26 shaper Exp $
  * 
  * lookuplet - a utility for quickly looking up information
  * Copyright (C) 2001 Michael Bayne
@@ -84,7 +84,7 @@ main (int argc, char** argv)
 #endif
 
     if (applet_mode) {
-        /* intialize; this will basically set up the applet, corba and
+        /* initialize; this will basically set up the applet, corba and
            call gnome_init() */
         applet_widget_init(PACKAGE, VERSION, argc, argv, NULL, 0, NULL);
 

projects/lookuplet/src/c/querybox.c

@@ -1,5 +1,5 @@
 /**
- * $Id: querybox.c,v 1.8 2001/08/21 18:46:10 mdb Exp $
+ * $Id: querybox.c,v 1.9 2002/03/14 16:45:26 shaper Exp $
  * 
  * lookuplet - a utility for quickly looking up information
  * Copyright (C) 2001 Michael Bayne
@@ -27,16 +27,25 @@
 
 #include "binding.h"
 #include "launcher.h"
+#include "history.h"
 #include "keysym-util.h"
 #include "preferences.h"
 #include "lookuplet.h"
 #include "querybox.h"
 
+/* the query text entry field */
 static GtkWidget* _query;
 
 /* used by url_p */
 #define MATCH_PREFIX(text, prefix) !strncmp(text, prefix, sizeof(prefix)-1)
 
+/* key codes for navigating the entry history */
+#define NEXT_HISTORY_KEY (GDK_Up)
+#define PREVIOUS_HISTORY_KEY (GDK_Down)
+
+/* key code for auto-completion of a partial entry */
+#define AUTO_COMPLETE_KEY (GDK_Tab)
+
 /**
  * A very primitive function to try to determine if the selection is a URL
  * of some sort.
@@ -95,6 +104,41 @@ selection_received (GtkWidget* widget, GtkSelectionData* selection_data,
     }
 }
 
+static gint
+handle_special_keys (GtkWidget* widget, GdkEventKey* ek)
+{
+    const gchar* entry = NULL;
+
+    switch (ek->keyval) {
+    case NEXT_HISTORY_KEY:
+    case PREVIOUS_HISTORY_KEY:
+        /* retrieve the sought-after historical entry */
+        entry = lk_get_history(ek->keyval == NEXT_HISTORY_KEY);
+        break;
+
+    case AUTO_COMPLETE_KEY: {
+        /* get the terms from the query box */
+        gchar* text = gtk_editable_get_chars(GTK_EDITABLE(widget), 0, -1);
+        /* seek an expanded historical entry for the current text */
+        entry = lk_get_history_expand(text);
+        }
+        break;
+    }
+
+    /* if we've an entry, fill it in and we're done */
+    if (entry != NULL) {
+        /* place the entry in the text field */
+        gtk_entry_set_text(GTK_ENTRY(widget), entry);
+
+        /* select the text in the entry so that it can be easily replaced */
+        gtk_editable_select_region(GTK_EDITABLE(_query), 0, strlen(entry));
+
+        return TRUE;
+    }
+
+    return FALSE;
+}
+
 static gint
 key_pressed (GtkWidget* widget, GdkEvent* event, gpointer callback_data)
 {
@@ -103,6 +147,11 @@ key_pressed (GtkWidget* widget, GdkEvent* event, gpointer callback_data)
     gint handled = FALSE, i;
     gchar* keystr;
 
+    /* handle special keystrokes such as history and auto-complete */
+    if (handle_special_keys(widget, ek)) {
+        return TRUE;
+    }
+
     /* ignore plain or shifted keystrokes */
     if (ek->state <= 1) {
 	return FALSE;
@@ -110,6 +159,9 @@ key_pressed (GtkWidget* widget, GdkEvent* event, gpointer callback_data)
 
     /* otherwise convert the key combo to a name and look it up */
     keystr = convert_keysym_state_to_string(ek->keyval, ek->state);
+    if (keystr == NULL) {
+        return FALSE;
+    }
     bindings = lk_prefs_get_bindings();
 
     for (i = 0; i < bindings->len; i++) {
@@ -118,9 +170,11 @@ key_pressed (GtkWidget* widget, GdkEvent* event, gpointer callback_data)
 	    /* get the terms from the query box */
 	    gchar* search_text =
 		gtk_editable_get_chars(GTK_EDITABLE(widget), 0, -1);
+            /* save this entry in the history */
+            lk_add_history(search_text);
 	    /* launch the appropriate thing */
 	    lk_launcher_launch(binding, search_text);
-	    g_free(search_text);
+            g_free(search_text);
             if (applet_mode) {
                 /* clear out the contents of the entry box */
                 gtk_entry_set_text(GTK_ENTRY(widget), "");
@@ -151,9 +205,11 @@ launch (GtkWidget* widget, gpointer data)
      * instead of pressing some special key combination) */
     gchar* search_text = gtk_editable_get_chars(GTK_EDITABLE(widget), 0, -1);
     lk_launcher_launch(NULL, search_text);
-    g_free(search_text);
 
     if (applet_mode) {
+        /* save this entry in the history */
+        lk_add_history(search_text);
+        g_free(search_text);
         /* clear out the contents of the entry box */
         gtk_entry_set_text(GTK_ENTRY(widget), "");
     } else {
@@ -195,6 +251,9 @@ lk_querybox_create (void)
         gtk_box_pack_start(GTK_BOX(hbox), prefs, FALSE, FALSE, 0);
     }
 
+    /* create the array of history commands */
+    lk_init_history();
+
     return hbox;
 }