netsurf/desktop/selection.c

1026 lines
26 KiB
C

/*
* Copyright 2005 Adrian Lees <adrianl@users.sourceforge.net>
* Copyright 2008 Michael Drake <tlsa@netsurf-browser.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf 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; version 2 of the License.
*
* NetSurf 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, see <http://www.gnu.org/licenses/>.
*/
/** \file
* Text selection within browser windows (implementation).
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include "content/hlcache.h"
#include "desktop/gui.h"
#include "desktop/mouse.h"
#include "desktop/plotters.h"
#include "desktop/save_text.h"
#include "desktop/selection.h"
#include "render/box.h"
#include "render/font.h"
#include "render/form.h"
#include "render/textplain.h"
#include "utils/log.h"
#include "utils/utf8.h"
#include "utils/utils.h"
/**
* Text selection works by labelling each node in the box tree with its
* start index in the textual representation of the tree's content.
*
* Text input fields and text areas have their own number spaces so that
* they can be relabelled more efficiently when editing (rather than relabel
* the entire box tree) and so that selections are either wholly within
* or wholly without the textarea/input box.
*/
#define IS_INPUT(box) ((box) && (box)->gadget && \
((box)->gadget->type == GADGET_TEXTAREA || \
(box)->gadget->type == GADGET_TEXTBOX || \
(box)->gadget->type == GADGET_PASSWORD))
/** check whether the given text box is in the same number space as the
current selection; number spaces are identified by their uppermost nybble */
#define NUMBER_SPACE(x) ((x) & 0xF0000000U)
#define SAME_SPACE(s, offset) (NUMBER_SPACE((s)->max_idx) == NUMBER_SPACE(offset))
struct rdw_info {
bool inited;
struct rect r;
};
static bool redraw_handler(const char *text, size_t length, struct box *box,
void *handle, const char *whitespace_text,
size_t whitespace_length);
static void selection_redraw(struct selection *s, unsigned start_idx,
unsigned end_idx);
static bool save_handler(const char *text, size_t length, struct box *box,
void *handle, const char *whitespace_text,
size_t whitespace_length);
static bool selected_part(struct box *box, unsigned start_idx, unsigned end_idx,
unsigned *start_offset, unsigned *end_offset);
static bool traverse_tree(struct box *box, unsigned start_idx, unsigned end_idx,
unsigned int num_space, seln_traverse_handler handler,
void *handle, save_text_whitespace *before, bool *first,
bool do_marker);
static struct box *get_box(struct box *b, unsigned offset, size_t *pidx);
/**
* Creates a new selection object associated with a browser window.
*
* \param bw browser window
*/
struct selection *selection_create(struct browser_window *bw)
{
struct selection *s = calloc(1, sizeof(struct selection));
if (s) {
s->bw = bw;
s->root = NULL;
s->drag_state = DRAG_NONE;
selection_clear(s, false);
}
return s;
}
/**
* Destroys a selection object, without updating the
* owning window (caller should call selection_clear()
* first if update is desired)
*
* \param s selection object
*/
void selection_destroy(struct selection *s)
{
free(s);
}
/**
* Initialise the selection object to use the given box subtree as its root,
* ie. selections are confined to that subtree, whilst maintaining the current
* selection whenever possible because, for example, it's just the page being
* resized causing the layout to change.
*
* \param s selection object
* \param root the box (page/textarea) to be used as the root node for this selection
*/
void selection_reinit(struct selection *s, struct box *root)
{
unsigned root_idx;
assert(s);
if (IS_INPUT(root)) {
static int next_idx = 0;
if (!++next_idx) next_idx = 1;
root_idx = next_idx << 28;
}
else
root_idx = 0;
// if (s->root == root) {
// /* keep the same number space as before, because we want
// to keep the selection too */
// root_idx = (s->max_idx & 0xF0000000U);
// }
// else {
// static int next_idx = 0;
// root_idx = (next_idx++) << 28;
// }
s->root = root;
if (root) {
s->max_idx = selection_label_subtree(root, root_idx);
}
else {
hlcache_handle *c = s->bw->current_content;
if (c && content_get_type(c) == CONTENT_TEXTPLAIN)
s->max_idx = textplain_size(c);
else
s->max_idx = 0;
}
if (s->defined) {
if (s->end_idx > s->max_idx) s->end_idx = s->max_idx;
if (s->start_idx > s->max_idx) s->start_idx = s->max_idx;
s->defined = (s->end_idx > s->start_idx);
}
}
/**
* Initialise the selection object to use the given box subtree as its root,
* ie. selections are confined to that subtree.
*
* \param s selection object
* \param root the box (page/textarea) to be used as the root node for this selection
*/
void selection_init(struct selection *s, struct box *root)
{
if (s->defined)
selection_clear(s, true);
s->defined = false;
s->start_idx = 0;
s->end_idx = 0;
s->drag_state = DRAG_NONE;
selection_reinit(s, root);
}
/**
* Indicate whether the selected text is read only, ie. cannot be modified.
*
* \param s selection object
* \return true iff the selection is read only
*/
bool selection_read_only(struct selection *s)
{
return !s->root || !NUMBER_SPACE(s->root->byte_offset);
}
/**
* Label each text box in the given box subtree with its position
* in a textual representation of the content.
*
* \param s selection object
* \param node box at root of subtree
* \param idx current position within textual representation
* \return updated position
*/
unsigned selection_label_subtree(struct box *box, unsigned idx)
{
struct box *child = box->children;
box->byte_offset = idx;
if (box->text)
idx += box->length + box->space;
while (child) {
if (!IS_INPUT(child)) {
if (child->list_marker)
idx = selection_label_subtree(
child->list_marker, idx);
idx = selection_label_subtree(child, idx);
}
child = child->next;
}
return idx;
}
/**
* Handles mouse clicks (including drag starts) in or near a selection
*
* \param s selection object
* \param mouse state of mouse buttons and modifier keys
* \param idx byte offset within textual representation
*
* \return true iff the click has been handled by the selection code
*/
bool selection_click(struct selection *s, browser_mouse_state mouse,
unsigned idx)
{
browser_mouse_state modkeys =
(mouse & (BROWSER_MOUSE_MOD_1 | BROWSER_MOUSE_MOD_2));
int pos = -1; /* 0 = inside selection, 1 = after it */
if (!SAME_SPACE(s, idx))
return false; /* not our problem */
if (selection_defined(s)) {
if (idx > s->start_idx) {
if (idx <= s->end_idx)
pos = 0;
else
pos = 1;
}
}
if (!pos &&
((mouse & BROWSER_MOUSE_DRAG_1) ||
(modkeys && (mouse & BROWSER_MOUSE_DRAG_2)))) {
/* drag-saving selection */
assert(s->bw);
gui_drag_save_selection(s, s->bw->window);
}
else if (!modkeys) {
if (pos && (mouse & BROWSER_MOUSE_PRESS_1))
/* Clear the selection if mouse is pressed outside the selection,
* Otherwise clear on release (to allow for drags) */
selection_clear(s, true);
else if (mouse & BROWSER_MOUSE_DRAG_1) {
/* start new selection drag */
selection_clear(s, true);
selection_set_start(s, idx);
selection_set_end(s, idx);
s->drag_state = DRAG_END;
gui_start_selection(s->bw->window);
}
else if (mouse & BROWSER_MOUSE_DRAG_2) {
/* adjust selection, but only if there is one */
if (!selection_defined(s))
return false; /* ignore Adjust drags */
if (pos >= 0) {
selection_set_end(s, idx);
s->drag_state = DRAG_END;
}
else {
selection_set_start(s, idx);
s->drag_state = DRAG_START;
}
gui_start_selection(s->bw->window);
}
/* Selection should be cleared when button is released but in
* the RO interface click is the same as press */
// else if (!pos && (mouse & BROWSER_MOUSE_CLICK_1)) {
// /* clear selection */
// selection_clear(s, true);
// s->drag_state = DRAG_NONE;
// }
else if (mouse & BROWSER_MOUSE_CLICK_2) {
/* ignore Adjust clicks when there's no selection */
if (!selection_defined(s))
return false;
if (pos >= 0)
selection_set_end(s, idx);
else
selection_set_start(s, idx);
s->drag_state = DRAG_NONE;
}
else
return false;
}
else {
/* not our problem */
return false;
}
/* this mouse click is selection-related */
return true;
}
/**
* Handles movements related to the selection, eg. dragging of start and
* end points.
*
* \param s selection object
* \param mouse state of mouse buttons and modifier keys
* \param idx byte offset within text representation
*/
void selection_track(struct selection *s, browser_mouse_state mouse,
unsigned idx)
{
if (!SAME_SPACE(s, idx))
return;
switch (s->drag_state) {
case DRAG_START:
if (idx > s->end_idx) {
unsigned old_end = s->end_idx;
selection_set_end(s, idx);
selection_set_start(s, old_end);
s->drag_state = DRAG_END;
}
else
selection_set_start(s, idx);
break;
case DRAG_END:
if (idx < s->start_idx) {
unsigned old_start = s->start_idx;
selection_set_start(s, idx);
selection_set_end(s, old_start);
s->drag_state = DRAG_START;
}
else
selection_set_end(s, idx);
break;
default:
break;
}
}
/**
* Tests whether a text box lies partially within the given range of
* byte offsets, returning the start and end indexes of the bytes
* that are enclosed.
*
* \param box box to be tested
* \param start_idx byte offset of start of range
* \param end_idx byte offset of end of range
* \param start_offset receives the start offset of the selected part
* \param end_offset receives the end offset of the selected part
* \return true iff the range encloses at least part of the box
*/
bool selected_part(struct box *box, unsigned start_idx, unsigned end_idx,
unsigned *start_offset, unsigned *end_offset)
{
size_t box_length = box->length + box->space;
if (box_length > 0) {
if (box->byte_offset >= start_idx &&
box->byte_offset + box_length <= end_idx) {
/* fully enclosed */
*start_offset = 0;
*end_offset = box_length;
return true;
}
else if (box->byte_offset + box_length > start_idx &&
box->byte_offset < end_idx) {
/* partly enclosed */
int offset = 0;
int len;
if (box->byte_offset < start_idx)
offset = start_idx - box->byte_offset;
len = box_length - offset;
if (box->byte_offset + box_length > end_idx)
len = end_idx - (box->byte_offset + offset);
*start_offset = offset;
*end_offset = offset + len;
return true;
}
}
return false;
}
/**
* Traverse the given box subtree, calling the handler function (with its handle)
* for all boxes that lie (partially) within the given range
*
* \param box box subtree
* \param start_idx start of range within textual representation (bytes)
* \param end_idx end of range
* \param num_space number space of the selection
* \param handler handler function to call
* \param handle handle to pass
* \param before type of whitespace to place before next encountered text
* \param first whether this is the first box with text
* \param do_marker whether deal enter any marker box
* \return false iff traversal abandoned part-way through
*/
bool traverse_tree(struct box *box, unsigned start_idx, unsigned end_idx,
unsigned int num_space, seln_traverse_handler handler,
void *handle, save_text_whitespace *before, bool *first,
bool do_marker)
{
struct box *child;
const char *whitespace_text = "";
size_t whitespace_length = 0;
assert(box);
/* If selection starts inside marker */
if (box->parent && box->parent->list_marker == box && !do_marker) {
/* set box to main list element */
box = box->parent;
}
/* If box has a list marker */
if (box->list_marker) {
/* do the marker box before continuing with the rest of the
* list element */
if (!traverse_tree(box->list_marker, start_idx, end_idx,
num_space, handler, handle, before, first,
true))
return false;
}
/* we can prune this subtree, it's after the selection */
if (box->byte_offset >= end_idx)
return true;
/* read before calling the handler in case it modifies the tree */
child = box->children;
/* If nicely formatted output of the selected text is required, work
* out what whitespace should be placed before the next bit of text */
if (before) {
save_text_solve_whitespace(box, first, before, &whitespace_text,
&whitespace_length);
}
else {
whitespace_text = NULL;
}
if (num_space == NUMBER_SPACE(box->byte_offset) &&
box->type != BOX_BR &&
!((box->type == BOX_FLOAT_LEFT ||
box->type == BOX_FLOAT_RIGHT) &&
!box->text)) {
unsigned start_offset;
unsigned end_offset;
if (selected_part(box, start_idx, end_idx, &start_offset,
&end_offset)) {
if (!handler(box->text + start_offset, min(box->length,
end_offset) - start_offset,
box, handle, whitespace_text,
whitespace_length))
return false;
if (before) {
*first = false;
*before = WHITESPACE_NONE;
}
}
}
/* find the first child that could lie partially within the selection;
* this is important at the top-levels of the tree for pruning subtrees
* that lie entirely before the selection */
if (child) {
struct box *next = child->next;
while (next && next->byte_offset < start_idx) {
child = next;
next = child->next;
}
while (child) {
/* read before calling the handler in case it modifies
* the tree */
struct box *next = child->next;
if (!traverse_tree(child, start_idx, end_idx, num_space,
handler, handle, before, first, false))
return false;
child = next;
}
}
return true;
}
/**
* Traverse the current selection, calling the handler function (with its
* handle) for all boxes that lie (partially) within the given range
*
* \param handler handler function to call
* \param handle handle to pass
* \return false iff traversal abandoned part-way through
*/
bool selection_traverse(struct selection *s, seln_traverse_handler handler,
void *handle)
{
hlcache_handle *c;
save_text_whitespace before = WHITESPACE_NONE;
bool first = true;
const char *text;
size_t length;
if (!selection_defined(s))
return true; /* easy case, nothing to do */
if (s->root)
return traverse_tree(s->root, s->start_idx, s->end_idx,
NUMBER_SPACE(s->max_idx), handler, handle,
&before, &first, false);
c = s->bw->current_content;
if (!c) return true;
text = textplain_get_raw_data(c, s->start_idx,
s->end_idx, &length);
if (text && !handler(text, length, NULL, handle, NULL, 0))
return false;
return true;
}
/**
* Selection traversal handler for redrawing the screen when the selection
* has been altered.
*
* \param text pointer to text string
* \param length length of text to be appended (bytes)
* \param box pointer to text box being (partially) added
* \param handle unused handle, we don't need one
* \param whitespace_text whitespace to place before text for formatting
* may be NULL
* \param whitespace_length length of whitespace_text
* \return true iff successful and traversal should continue
*/
bool redraw_handler(const char *text, size_t length, struct box *box,
void *handle, const char *whitespace_text,
size_t whitespace_length)
{
if (box) {
struct rdw_info *r = (struct rdw_info*)handle;
int width, height, space_width;
int x, y;
plot_font_style_t fstyle;
font_plot_style_from_css(box->style, &fstyle);
/* \todo - it should be possible to reduce the redrawn area by
* considering the 'text', 'length' and 'space' parameters */
box_coords(box, &x, &y);
width = box->padding[LEFT] + box->width + box->padding[RIGHT];
height = box->padding[TOP] + box->height + box->padding[BOTTOM];
if (box->type == BOX_TEXT && box->space &&
nsfont.font_width(&fstyle, " ", 1, &space_width))
width += space_width;
if (r->inited) {
if (x < r->r.x0) r->r.x0 = x;
if (y < r->r.y0) r->r.y0 = y;
if (x + width > r->r.x1) r->r.x1 = x + width;
if (y + height > r->r.y1) r->r.y1 = y + height;
}
else {
r->inited = true;
r->r.x0 = x;
r->r.y0 = y;
r->r.x1 = x + width;
r->r.y1 = y + height;
}
}
return true;
}
/**
* Redraws the given range of text.
*
* \param s selection object
* \param start_idx start offset (bytes) within the textual representation
* \param end_idx end offset (bytes) within the textual representation
*/
void selection_redraw(struct selection *s, unsigned start_idx, unsigned end_idx)
{
struct rdw_info rdw;
assert(end_idx >= start_idx);
rdw.inited = false;
if (s->root) {
if (!traverse_tree(s->root, start_idx, end_idx,
NUMBER_SPACE(s->max_idx), redraw_handler, &rdw,
NULL, NULL, false))
return;
}
else {
hlcache_handle *c = s->bw->current_content;
if (c && content_get_type(c) == CONTENT_TEXTPLAIN &&
end_idx > start_idx) {
textplain_coords_from_range(c, start_idx,
end_idx, &rdw.r);
rdw.inited = true;
}
}
if (rdw.inited)
browser_window_redraw_rect(s->bw, rdw.r.x0, rdw.r.y0,
rdw.r.x1 - rdw.r.x0, rdw.r.y1 - rdw.r.y0);
}
/**
* Clears the current selection, optionally causing the screen to be updated.
*
* \param s selection object
* \param redraw true iff the previously selected region of the browser
* window should be redrawn
*/
void selection_clear(struct selection *s, bool redraw)
{
int old_start, old_end;
bool was_defined;
assert(s);
was_defined = selection_defined(s);
old_start = s->start_idx;
old_end = s->end_idx;
s->defined = false;
s->start_idx = 0;
s->end_idx = 0;
gui_clear_selection(s->bw->window);
if (redraw && was_defined)
selection_redraw(s, old_start, old_end);
}
/**
* Selects all the text within the box subtree controlled by
* this selection object, updating the screen accordingly.
*
* \param s selection object
*/
void selection_select_all(struct selection *s)
{
assert(s);
s->defined = true;
if (IS_INPUT(s->root))
selection_set_start(s, s->root->children->children->byte_offset);
else
selection_set_start(s, 0);
selection_set_end(s, s->max_idx);
}
/**
* Set the start position of the current selection, updating the screen.
*
* \param s selection object
* \param offset byte offset within textual representation
*/
void selection_set_start(struct selection *s, unsigned offset)
{
bool was_defined = selection_defined(s);
unsigned old_start = s->start_idx;
s->start_idx = offset;
s->defined = (s->start_idx < s->end_idx);
if (s->defined && s->root && s->root->gadget) {
/* update the caret text_box and offset so that it stays at the
* beginning of the selection */
s->root->gadget->caret_text_box = selection_get_start(s,
&s->root->gadget->caret_box_offset);
assert(s->root->gadget->caret_text_box != NULL);
}
if (was_defined) {
if (offset < old_start)
selection_redraw(s, s->start_idx, old_start);
else
selection_redraw(s, old_start, s->start_idx);
}
else if (selection_defined(s))
selection_redraw(s, s->start_idx, s->end_idx);
}
/**
* Set the end position of the current selection, updating the screen.
*
* \param s selection object
* \param offset byte offset within textual representation
*/
void selection_set_end(struct selection *s, unsigned offset)
{
bool was_defined = selection_defined(s);
unsigned old_end = s->end_idx;
s->end_idx = offset;
s->defined = (s->start_idx < s->end_idx);
if (was_defined) {
if (offset < old_end)
selection_redraw(s, s->end_idx, old_end);
else
selection_redraw(s, old_end, s->end_idx);
}
else if (selection_defined(s))
selection_redraw(s, s->start_idx, s->end_idx);
}
/**
* Get the box and index of the specified byte offset within the
* textual representation.
*
* \param b root node of search
* \param offset byte offset within textual representation
* \param pidx receives byte index of selection start point within box
* \return ptr to box, or NULL if no selection defined
*/
struct box *get_box(struct box *b, unsigned offset, size_t *pidx)
{
struct box *child = b->children;
if (b->text) {
if (offset >= b->byte_offset &&
offset <= b->byte_offset + b->length + b->space) {
/* it's in this box */
*pidx = offset - b->byte_offset;
return b;
}
}
/* find the first child that could contain this offset */
if (child) {
struct box *next = child->next;
while (next && next->byte_offset < offset) {
child = next;
next = child->next;
}
return get_box(child, offset, pidx);
}
return NULL;
}
/**
* Get the box and index of the selection start, if defined.
*
* \param s selection object
* \param pidx receives byte index of selection start point within box
* \return ptr to box, or NULL if no selection defined
*/
struct box *selection_get_start(struct selection *s, size_t *pidx)
{
return (s->defined ? get_box(s->root, s->start_idx, pidx) : NULL);
}
/**
* Get the box and index of the selection end, if defined.
*
* \param s selection object
* \param pidx receives byte index of selection end point within box
* \return ptr to box, or NULL if no selection defined.
*/
struct box *selection_get_end(struct selection *s, size_t *pidx)
{
return (s->defined ? get_box(s->root, s->end_idx, pidx) : NULL);
}
/**
* Tests whether a text range lies partially within the selection, if there is
* a selection defined, returning the start and end indexes of the bytes
* that should be selected.
*
* \param s the selection object
* \param start byte offset of start of text
* \param start_idx receives the start index (in bytes) of the highlighted portion
* \param end_idx receives the end index (in bytes)
* \return true iff part of the given box lies within the selection
*/
bool selection_highlighted(struct selection *s, unsigned start, unsigned end,
unsigned *start_idx, unsigned *end_idx)
{
/* caller should have checked first for efficiency */
assert(s);
assert(selection_defined(s));
if (end <= s->start_idx || start >= s->end_idx)
return false;
*start_idx = (s->start_idx >= start) ? (s->start_idx - start) : 0;
*end_idx = min(end, s->end_idx) - start;
return true;
// assert(box);
// assert(IS_TEXT(box));
// return selected_part(box, s->start_idx, s->end_idx, start_idx, end_idx);
}
/**
* Selection traversal handler for saving the text to a file.
*
* \param text pointer to text being added, or NULL for newline
* \param length length of text to be appended (bytes)
* \param box pointer to text box (or NULL for textplain content)
* \param handle our save_state workspace pointer
* \param whitespace_text whitespace to place before text for formatting
* may be NULL
* \param whitespace_length length of whitespace_text
* \return true iff the file writing succeeded and traversal should continue.
*/
bool save_handler(const char *text, size_t length, struct box *box,
void *handle, const char *whitespace_text,
size_t whitespace_length)
{
struct save_text_state *sv = handle;
size_t new_length;
int space = 0;
assert(sv);
if (box->space > 0)
space = 1;
if (whitespace_text)
length += whitespace_length;
new_length = sv->length + whitespace_length + length + space;
if (new_length >= sv->alloc) {
size_t new_alloc = sv->alloc + (sv->alloc / 4);
char *new_block;
if (new_alloc < new_length) new_alloc = new_length;
new_block = realloc(sv->block, new_alloc);
if (!new_block) return false;
sv->block = new_block;
sv->alloc = new_alloc;
}
if (whitespace_text) {
memcpy(sv->block + sv->length, whitespace_text,
whitespace_length);
}
memcpy(sv->block + sv->length + whitespace_length, text, length);
sv->length += length;
if (space == 1)
sv->block[sv->length++] = ' ';
return true;
}
/**
* Save the given selection to a file.
*
* \param s selection object
* \param path pathname to be used
* \return true iff the save succeeded
*/
bool selection_save_text(struct selection *s, const char *path)
{
hlcache_handle *c = s->bw->current_content;
struct save_text_state sv = { NULL, 0, 0 };
utf8_convert_ret ret;
char *result;
FILE *out;
assert(c);
if (!selection_traverse(s, save_handler, &sv)) {
free(sv.block);
return false;
}
if (!sv.block)
return false;
ret = utf8_to_local_encoding(sv.block, sv.length, &result);
free(sv.block);
if (ret != UTF8_CONVERT_OK) {
LOG(("failed to convert to local encoding, return %d", ret));
return false;
}
out = fopen(path, "w");
if (out) {
int res = fputs(result, out);
if (res < 0) {
LOG(("Warning: writing data failed"));
}
res = fputs("\n", out);
fclose(out);
free(result);
return (res != EOF);
}
free(result);
return false;
}
/**
* Adjust the selection to reflect a change in the selected text,
* eg. editing in a text area/input field.
*
* \param s selection object
* \param byte_offset byte offset of insertion/removal point
* \param change byte size of change, +ve = insertion, -ve = removal
* \param redraw true iff the screen should be updated
*/
void selection_update(struct selection *s, size_t byte_offset,
int change, bool redraw)
{
if (selection_defined(s) &&
byte_offset >= s->start_idx &&
byte_offset < s->end_idx)
{
if (change > 0)
s->end_idx += change;
else
s->end_idx +=
max(change, (int)(byte_offset - s->end_idx));
}
}