Learning_GTK4_tree/gtk/gtkentrybuffer.c

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2023-12-12 11:36:42 +01:00
/* gtkentrybuffer.c
* Copyright (C) 2009 Stefan Walter <stef@memberwebs.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "gtkentrybuffer.h"
#include "gtkmarshalers.h"
#include "gtkprivate.h"
#include "gtkwidget.h"
#include <gdk/gdk.h>
#include <string.h>
/**
* GtkEntryBuffer:
*
* A `GtkEntryBuffer` hold the text displayed in a `GtkText` widget.
*
* A single `GtkEntryBuffer` object can be shared by multiple widgets
* which will then share the same text content, but not the cursor
* position, visibility attributes, icon etc.
*
* `GtkEntryBuffer` may be derived from. Such a derived class might allow
* text to be stored in an alternate location, such as non-pageable memory,
* useful in the case of important passwords. Or a derived class could
* integrate with an applications concept of undo/redo.
*/
/* Initial size of buffer, in bytes */
#define MIN_SIZE 16
enum {
PROP_0,
PROP_TEXT,
PROP_LENGTH,
PROP_MAX_LENGTH,
NUM_PROPERTIES
};
static GParamSpec *entry_buffer_props[NUM_PROPERTIES] = { NULL, };
enum {
INSERTED_TEXT,
DELETED_TEXT,
LAST_SIGNAL
};
static guint signals[LAST_SIGNAL] = { 0 };
typedef struct _GtkEntryBufferPrivate GtkEntryBufferPrivate;
struct _GtkEntryBufferPrivate
{
/* Only valid if this class is not derived */
char *normal_text;
gsize normal_text_size;
gsize normal_text_bytes;
guint normal_text_chars;
int max_length;
};
G_DEFINE_TYPE_WITH_PRIVATE (GtkEntryBuffer, gtk_entry_buffer, G_TYPE_OBJECT)
/* --------------------------------------------------------------------------------
* DEFAULT IMPLEMENTATIONS OF TEXT BUFFER
*
* These may be overridden by a derived class, behavior may be changed etc...
* The normal_text and normal_text_xxxx fields may not be valid when
* this class is derived from.
*/
/* Overwrite a memory that might contain sensitive information. */
static void
trash_area (char *area,
gsize len)
{
volatile char *varea = (volatile char *)area;
while (len-- > 0)
*varea++ = 0;
}
static const char *
gtk_entry_buffer_normal_get_text (GtkEntryBuffer *buffer,
gsize *n_bytes)
{
GtkEntryBufferPrivate *priv = gtk_entry_buffer_get_instance_private (buffer);
if (n_bytes)
*n_bytes = priv->normal_text_bytes;
if (!priv->normal_text)
return "";
return priv->normal_text;
}
static guint
gtk_entry_buffer_normal_get_length (GtkEntryBuffer *buffer)
{
GtkEntryBufferPrivate *priv = gtk_entry_buffer_get_instance_private (buffer);
return priv->normal_text_chars;
}
static guint
gtk_entry_buffer_normal_insert_text (GtkEntryBuffer *buffer,
guint position,
const char *chars,
guint n_chars)
{
GtkEntryBufferPrivate *pv = gtk_entry_buffer_get_instance_private (buffer);
gsize prev_size;
gsize n_bytes;
gsize at;
n_bytes = g_utf8_offset_to_pointer (chars, n_chars) - chars;
/* Need more memory */
if (n_bytes + pv->normal_text_bytes + 1 > pv->normal_text_size)
{
char *et_new;
prev_size = pv->normal_text_size;
/* Calculate our new buffer size */
while (n_bytes + pv->normal_text_bytes + 1 > pv->normal_text_size)
{
if (pv->normal_text_size == 0)
pv->normal_text_size = MIN_SIZE;
else
{
if (2 * pv->normal_text_size < GTK_ENTRY_BUFFER_MAX_SIZE)
pv->normal_text_size *= 2;
else
{
pv->normal_text_size = GTK_ENTRY_BUFFER_MAX_SIZE;
if (n_bytes > pv->normal_text_size - pv->normal_text_bytes - 1)
{
n_bytes = pv->normal_text_size - pv->normal_text_bytes - 1;
n_bytes = g_utf8_find_prev_char (chars, chars + n_bytes + 1) - chars;
n_chars = g_utf8_strlen (chars, n_bytes);
}
break;
}
}
}
/* Could be a password, so can't leave stuff in memory. */
et_new = g_malloc (pv->normal_text_size);
memcpy (et_new, pv->normal_text, MIN (prev_size, pv->normal_text_size));
trash_area (pv->normal_text, prev_size);
g_free (pv->normal_text);
pv->normal_text = et_new;
}
/* Actual text insertion */
at = g_utf8_offset_to_pointer (pv->normal_text, position) - pv->normal_text;
memmove (pv->normal_text + at + n_bytes, pv->normal_text + at, pv->normal_text_bytes - at);
memcpy (pv->normal_text + at, chars, n_bytes);
/* Book keeping */
pv->normal_text_bytes += n_bytes;
pv->normal_text_chars += n_chars;
pv->normal_text[pv->normal_text_bytes] = '\0';
gtk_entry_buffer_emit_inserted_text (buffer, position, chars, n_chars);
return n_chars;
}
static guint
gtk_entry_buffer_normal_delete_text (GtkEntryBuffer *buffer,
guint position,
guint n_chars)
{
GtkEntryBufferPrivate *pv = gtk_entry_buffer_get_instance_private (buffer);
if (position > pv->normal_text_chars)
position = pv->normal_text_chars;
if (position + n_chars > pv->normal_text_chars)
n_chars = pv->normal_text_chars - position;
if (n_chars > 0)
gtk_entry_buffer_emit_deleted_text (buffer, position, n_chars);
return n_chars;
}
/* --------------------------------------------------------------------------------
*
*/
static void
gtk_entry_buffer_real_inserted_text (GtkEntryBuffer *buffer,
guint position,
const char *chars,
guint n_chars)
{
g_object_notify_by_pspec (G_OBJECT (buffer), entry_buffer_props[PROP_TEXT]);
g_object_notify_by_pspec (G_OBJECT (buffer), entry_buffer_props[PROP_LENGTH]);
}
static void
gtk_entry_buffer_real_deleted_text (GtkEntryBuffer *buffer,
guint position,
guint n_chars)
{
GtkEntryBufferPrivate *pv = gtk_entry_buffer_get_instance_private (buffer);
gsize start, end;
start = g_utf8_offset_to_pointer (pv->normal_text, position) - pv->normal_text;
end = g_utf8_offset_to_pointer (pv->normal_text, position + n_chars) - pv->normal_text;
memmove (pv->normal_text + start, pv->normal_text + end, pv->normal_text_bytes + 1 - end);
pv->normal_text_chars -= n_chars;
pv->normal_text_bytes -= (end - start);
/*
* Could be a password, make sure we don't leave anything sensitive after
* the terminating zero. Note, that the terminating zero already trashed
* one byte.
*/
trash_area (pv->normal_text + pv->normal_text_bytes + 1, end - start - 1);
g_object_notify_by_pspec (G_OBJECT (buffer), entry_buffer_props[PROP_TEXT]);
g_object_notify_by_pspec (G_OBJECT (buffer), entry_buffer_props[PROP_LENGTH]);
}
/* --------------------------------------------------------------------------------
*
*/
static void
gtk_entry_buffer_init (GtkEntryBuffer *buffer)
{
GtkEntryBufferPrivate *pv = gtk_entry_buffer_get_instance_private (buffer);
pv->normal_text = NULL;
pv->normal_text_chars = 0;
pv->normal_text_bytes = 0;
pv->normal_text_size = 0;
}
static void
gtk_entry_buffer_finalize (GObject *obj)
{
GtkEntryBuffer *buffer = GTK_ENTRY_BUFFER (obj);
GtkEntryBufferPrivate *pv = gtk_entry_buffer_get_instance_private (buffer);
if (pv->normal_text)
{
trash_area (pv->normal_text, pv->normal_text_size);
g_free (pv->normal_text);
pv->normal_text = NULL;
pv->normal_text_bytes = pv->normal_text_size = 0;
pv->normal_text_chars = 0;
}
G_OBJECT_CLASS (gtk_entry_buffer_parent_class)->finalize (obj);
}
static void
gtk_entry_buffer_set_property (GObject *obj,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkEntryBuffer *buffer = GTK_ENTRY_BUFFER (obj);
switch (prop_id)
{
case PROP_TEXT:
gtk_entry_buffer_set_text (buffer, g_value_get_string (value), -1);
break;
case PROP_MAX_LENGTH:
gtk_entry_buffer_set_max_length (buffer, g_value_get_int (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, prop_id, pspec);
break;
}
}
static void
gtk_entry_buffer_get_property (GObject *obj,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkEntryBuffer *buffer = GTK_ENTRY_BUFFER (obj);
switch (prop_id)
{
case PROP_TEXT:
g_value_set_string (value, gtk_entry_buffer_get_text (buffer));
break;
case PROP_LENGTH:
g_value_set_uint (value, gtk_entry_buffer_get_length (buffer));
break;
case PROP_MAX_LENGTH:
g_value_set_int (value, gtk_entry_buffer_get_max_length (buffer));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (obj, prop_id, pspec);
break;
}
}
static void
gtk_entry_buffer_class_init (GtkEntryBufferClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->finalize = gtk_entry_buffer_finalize;
gobject_class->set_property = gtk_entry_buffer_set_property;
gobject_class->get_property = gtk_entry_buffer_get_property;
klass->get_text = gtk_entry_buffer_normal_get_text;
klass->get_length = gtk_entry_buffer_normal_get_length;
klass->insert_text = gtk_entry_buffer_normal_insert_text;
klass->delete_text = gtk_entry_buffer_normal_delete_text;
klass->inserted_text = gtk_entry_buffer_real_inserted_text;
klass->deleted_text = gtk_entry_buffer_real_deleted_text;
/**
* GtkEntryBuffer:text: (attributes org.gtk.Property.get=gtk_entry_buffer_get_text org.gtk.Property.set=gtk_entry_buffer_set_text)
*
* The contents of the buffer.
*/
entry_buffer_props[PROP_TEXT] =
g_param_spec_string ("text", NULL, NULL,
"",
GTK_PARAM_READWRITE);
/**
* GtkEntryBuffer:length: (attributes org.gtk.Property.get=gtk_entry_buffer_get_length)
*
* The length (in characters) of the text in buffer.
*/
entry_buffer_props[PROP_LENGTH] =
g_param_spec_uint ("length", NULL, NULL,
0, GTK_ENTRY_BUFFER_MAX_SIZE, 0,
GTK_PARAM_READABLE);
/**
* GtkEntryBuffer:max-length: (attributes org.gtk.Property.get=gtk_entry_buffer_get_max_length org.gtk.Property.set=gtk_entry_buffer_set_max_length)
*
* The maximum length (in characters) of the text in the buffer.
*/
entry_buffer_props[PROP_MAX_LENGTH] =
g_param_spec_int ("max-length", NULL, NULL,
0, GTK_ENTRY_BUFFER_MAX_SIZE, 0,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
g_object_class_install_properties (gobject_class, NUM_PROPERTIES, entry_buffer_props);
/**
* GtkEntryBuffer::inserted-text:
* @buffer: a `GtkEntryBuffer`
* @position: the position the text was inserted at.
* @chars: The text that was inserted.
* @n_chars: The number of characters that were inserted.
*
* This signal is emitted after text is inserted into the buffer.
*/
signals[INSERTED_TEXT] = g_signal_new (I_("inserted-text"),
GTK_TYPE_ENTRY_BUFFER,
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (GtkEntryBufferClass, inserted_text),
NULL, NULL,
_gtk_marshal_VOID__UINT_STRING_UINT,
G_TYPE_NONE, 3,
G_TYPE_UINT,
G_TYPE_STRING,
G_TYPE_UINT);
g_signal_set_va_marshaller (signals[INSERTED_TEXT],
GTK_TYPE_ENTRY_BUFFER,
_gtk_marshal_VOID__UINT_STRING_UINTv);
/**
* GtkEntryBuffer::deleted-text:
* @buffer: a `GtkEntryBuffer`
* @position: the position the text was deleted at.
* @n_chars: The number of characters that were deleted.
*
* The text is altered in the default handler for this signal.
*
* If you want access to the text after the text has been modified,
* use %G_CONNECT_AFTER.
*/
signals[DELETED_TEXT] = g_signal_new (I_("deleted-text"),
GTK_TYPE_ENTRY_BUFFER,
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkEntryBufferClass, deleted_text),
NULL, NULL,
_gtk_marshal_VOID__UINT_UINT,
G_TYPE_NONE, 2,
G_TYPE_UINT,
G_TYPE_UINT);
g_signal_set_va_marshaller (signals[DELETED_TEXT],
GTK_TYPE_ENTRY_BUFFER,
_gtk_marshal_VOID__UINT_UINTv);
}
/* --------------------------------------------------------------------------------
*
*/
/**
* gtk_entry_buffer_new:
* @initial_chars: (nullable): initial buffer text
* @n_initial_chars: number of characters in @initial_chars, or -1
*
* Create a new `GtkEntryBuffer` object.
*
* Optionally, specify initial text to set in the buffer.
*
* Returns: A new `GtkEntryBuffer` object.
*/
GtkEntryBuffer*
gtk_entry_buffer_new (const char *initial_chars,
int n_initial_chars)
{
GtkEntryBuffer *buffer = g_object_new (GTK_TYPE_ENTRY_BUFFER, NULL);
if (initial_chars)
gtk_entry_buffer_set_text (buffer, initial_chars, n_initial_chars);
return buffer;
}
/**
* gtk_entry_buffer_get_length: (attributes org.gtk.Method.get_property=length)
* @buffer: a `GtkEntryBuffer`
*
* Retrieves the length in characters of the buffer.
*
* Returns: The number of characters in the buffer.
**/
guint
gtk_entry_buffer_get_length (GtkEntryBuffer *buffer)
{
GtkEntryBufferClass *klass;
g_return_val_if_fail (GTK_IS_ENTRY_BUFFER (buffer), 0);
klass = GTK_ENTRY_BUFFER_GET_CLASS (buffer);
g_return_val_if_fail (klass->get_length != NULL, 0);
return (*klass->get_length) (buffer);
}
/**
* gtk_entry_buffer_get_bytes:
* @buffer: a `GtkEntryBuffer`
*
* Retrieves the length in bytes of the buffer.
*
* See [method@Gtk.EntryBuffer.get_length].
*
* Returns: The byte length of the buffer.
**/
gsize
gtk_entry_buffer_get_bytes (GtkEntryBuffer *buffer)
{
GtkEntryBufferClass *klass;
gsize bytes = 0;
g_return_val_if_fail (GTK_IS_ENTRY_BUFFER (buffer), 0);
klass = GTK_ENTRY_BUFFER_GET_CLASS (buffer);
g_return_val_if_fail (klass->get_text != NULL, 0);
(*klass->get_text) (buffer, &bytes);
return bytes;
}
/**
* gtk_entry_buffer_get_text: (attributes org.gtk.Method.get_property=text)
* @buffer: a `GtkEntryBuffer`
*
* Retrieves the contents of the buffer.
*
* The memory pointer returned by this call will not change
* unless this object emits a signal, or is finalized.
*
* Returns: a pointer to the contents of the widget as a
* string. This string points to internally allocated storage
* in the buffer and must not be freed, modified or stored.
*/
const char *
gtk_entry_buffer_get_text (GtkEntryBuffer *buffer)
{
GtkEntryBufferClass *klass;
g_return_val_if_fail (GTK_IS_ENTRY_BUFFER (buffer), NULL);
klass = GTK_ENTRY_BUFFER_GET_CLASS (buffer);
g_return_val_if_fail (klass->get_text != NULL, NULL);
return (*klass->get_text) (buffer, NULL);
}
/**
* gtk_entry_buffer_set_text: (attributes org.gtk.Method.set_property=text)
* @buffer: a `GtkEntryBuffer`
* @chars: the new text
* @n_chars: the number of characters in @text, or -1
*
* Sets the text in the buffer.
*
* This is roughly equivalent to calling
* [method@Gtk.EntryBuffer.delete_text] and
* [method@Gtk.EntryBuffer.insert_text].
*
* Note that @n_chars is in characters, not in bytes.
**/
void
gtk_entry_buffer_set_text (GtkEntryBuffer *buffer,
const char *chars,
int n_chars)
{
g_return_if_fail (GTK_IS_ENTRY_BUFFER (buffer));
g_return_if_fail (chars != NULL);
g_object_freeze_notify (G_OBJECT (buffer));
gtk_entry_buffer_delete_text (buffer, 0, -1);
gtk_entry_buffer_insert_text (buffer, 0, chars, n_chars);
g_object_thaw_notify (G_OBJECT (buffer));
}
/**
* gtk_entry_buffer_set_max_length: (attributes org.gtk.Method.set_property=max-length)
* @buffer: a `GtkEntryBuffer`
* @max_length: the maximum length of the entry buffer, or 0 for no maximum.
* (other than the maximum length of entries.) The value passed in will
* be clamped to the range 0-65536.
*
* Sets the maximum allowed length of the contents of the buffer.
*
* If the current contents are longer than the given length, then
* they will be truncated to fit.
*/
void
gtk_entry_buffer_set_max_length (GtkEntryBuffer *buffer,
int max_length)
{
GtkEntryBufferPrivate *priv = gtk_entry_buffer_get_instance_private (buffer);
g_return_if_fail (GTK_IS_ENTRY_BUFFER (buffer));
max_length = CLAMP (max_length, 0, GTK_ENTRY_BUFFER_MAX_SIZE);
if (priv->max_length == max_length)
return;
if (max_length > 0 && gtk_entry_buffer_get_length (buffer) > max_length)
gtk_entry_buffer_delete_text (buffer, max_length, -1);
priv->max_length = max_length;
g_object_notify_by_pspec (G_OBJECT (buffer), entry_buffer_props[PROP_MAX_LENGTH]);
}
/**
* gtk_entry_buffer_get_max_length: (attributes org.gtk.Method.get_property=max-length)
* @buffer: a `GtkEntryBuffer`
*
* Retrieves the maximum allowed length of the text in @buffer.
*
* Returns: the maximum allowed number of characters
* in `GtkEntryBuffer`, or 0 if there is no maximum.
*/
int
gtk_entry_buffer_get_max_length (GtkEntryBuffer *buffer)
{
GtkEntryBufferPrivate *priv = gtk_entry_buffer_get_instance_private (buffer);
g_return_val_if_fail (GTK_IS_ENTRY_BUFFER (buffer), 0);
return priv->max_length;
}
/**
* gtk_entry_buffer_insert_text:
* @buffer: a `GtkEntryBuffer`
* @position: the position at which to insert text.
* @chars: the text to insert into the buffer.
* @n_chars: the length of the text in characters, or -1
*
* Inserts @n_chars characters of @chars into the contents of the
* buffer, at position @position.
*
* If @n_chars is negative, then characters from chars will be inserted
* until a null-terminator is found. If @position or @n_chars are out of
* bounds, or the maximum buffer text length is exceeded, then they are
* coerced to sane values.
*
* Note that the position and length are in characters, not in bytes.
*
* Returns: The number of characters actually inserted.
*/
guint
gtk_entry_buffer_insert_text (GtkEntryBuffer *buffer,
guint position,
const char *chars,
int n_chars)
{
GtkEntryBufferPrivate *pv = gtk_entry_buffer_get_instance_private (buffer);
GtkEntryBufferClass *klass;
guint length;
g_return_val_if_fail (GTK_IS_ENTRY_BUFFER (buffer), 0);
length = gtk_entry_buffer_get_length (buffer);
if (n_chars < 0)
n_chars = g_utf8_strlen (chars, -1);
/* Bring position into bounds */
if (position > length)
position = length;
/* Make sure not entering too much data */
if (pv->max_length > 0)
{
if (length >= pv->max_length)
n_chars = 0;
else if (length + n_chars > pv->max_length)
n_chars -= (length + n_chars) - pv->max_length;
}
if (n_chars == 0)
return 0;
klass = GTK_ENTRY_BUFFER_GET_CLASS (buffer);
g_return_val_if_fail (klass->insert_text != NULL, 0);
return (*klass->insert_text) (buffer, position, chars, n_chars);
}
/**
* gtk_entry_buffer_delete_text:
* @buffer: a `GtkEntryBuffer`
* @position: position at which to delete text
* @n_chars: number of characters to delete
*
* Deletes a sequence of characters from the buffer.
*
* @n_chars characters are deleted starting at @position.
* If @n_chars is negative, then all characters until the
* end of the text are deleted.
*
* If @position or @n_chars are out of bounds, then they
* are coerced to sane values.
*
* Note that the positions are specified in characters,
* not bytes.
*
* Returns: The number of characters deleted.
*/
guint
gtk_entry_buffer_delete_text (GtkEntryBuffer *buffer,
guint position,
int n_chars)
{
GtkEntryBufferClass *klass;
guint length;
g_return_val_if_fail (GTK_IS_ENTRY_BUFFER (buffer), 0);
length = gtk_entry_buffer_get_length (buffer);
if (n_chars < 0)
n_chars = length;
if (position > length)
position = length;
if (position + n_chars > length)
n_chars = length - position;
klass = GTK_ENTRY_BUFFER_GET_CLASS (buffer);
g_return_val_if_fail (klass->delete_text != NULL, 0);
return (*klass->delete_text) (buffer, position, n_chars);
}
/**
* gtk_entry_buffer_emit_inserted_text:
* @buffer: a `GtkEntryBuffer`
* @position: position at which text was inserted
* @chars: text that was inserted
* @n_chars: number of characters inserted
*
* Used when subclassing `GtkEntryBuffer`.
*/
void
gtk_entry_buffer_emit_inserted_text (GtkEntryBuffer *buffer,
guint position,
const char *chars,
guint n_chars)
{
g_return_if_fail (GTK_IS_ENTRY_BUFFER (buffer));
g_signal_emit (buffer, signals[INSERTED_TEXT], 0, position, chars, n_chars);
}
/**
* gtk_entry_buffer_emit_deleted_text:
* @buffer: a `GtkEntryBuffer`
* @position: position at which text was deleted
* @n_chars: number of characters deleted
*
* Used when subclassing `GtkEntryBuffer`.
*/
void
gtk_entry_buffer_emit_deleted_text (GtkEntryBuffer *buffer,
guint position,
guint n_chars)
{
g_return_if_fail (GTK_IS_ENTRY_BUFFER (buffer));
g_signal_emit (buffer, signals[DELETED_TEXT], 0, position, n_chars);
}