tdv/src/stardict-view.c

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/*
* StarDict GTK+ UI - dictionary view component
*
* Copyright (c) 2021, Přemysl Eric Janouch <p@janouch.name>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#include <gtk/gtk.h>
#include <glib/gi18n.h>
#include "stardict-view.h"
#include "utils.h"
typedef struct view_entry ViewEntry;
struct view_entry
{
gchar *word; ///< The word
gsize word_matched; ///< Initial matching bytes of the word
gchar *definition; ///< Definition lines, in Pango markup
PangoLayout *word_layout; ///< Ellipsized one-line layout or NULL
PangoLayout *definition_layout; ///< Multiline layout or NULL
};
static void
view_entry_destroy (ViewEntry *self)
{
g_free (self->word);
g_free (self->definition);
g_clear_object (&self->word_layout);
g_clear_object (&self->definition_layout);
g_slice_free1 (sizeof *self, self);
}
static ViewEntry *
view_entry_new (StardictIterator *iterator, const gchar *matched)
{
g_return_val_if_fail (stardict_iterator_is_valid (iterator), NULL);
StardictEntry *entry = stardict_iterator_get_entry (iterator);
g_return_val_if_fail (entry != NULL, NULL);
// Highlighting may change the rendition, so far it's easiest to recompute
// it on each search field change by rebuilding the list of view entries.
// The phonetics suffix would need to be stored separately.
const gchar *word = stardict_iterator_get_word (iterator);
GString *adjusted_word = g_string_new (word);
GPtrArray *definitions = g_ptr_array_new_full (2, g_free);
for (const GList *fields = stardict_entry_get_fields (entry); fields; )
{
const StardictEntryField *field = fields->data;
switch (field->type)
{
case STARDICT_FIELD_MEANING:
g_ptr_array_add (definitions,
g_markup_escape_text (field->data, -1));
break;
case STARDICT_FIELD_PANGO:
g_ptr_array_add (definitions, g_strdup (field->data));
break;
case STARDICT_FIELD_XDXF:
g_ptr_array_add (definitions,
xdxf_to_pango_markup_with_reduced_effort (field->data));
break;
case STARDICT_FIELD_PHONETIC:
g_string_append_printf (adjusted_word,
" /%s/", (const char *) field->data);
default:
// TODO: support more of them
break;
}
fields = fields->next;
}
g_object_unref (entry);
ViewEntry *ve = g_slice_alloc0 (sizeof *ve);
ve->word = g_string_free (adjusted_word, FALSE);
ve->word_matched = stardict_longest_common_collation_prefix
(iterator->owner, word, matched);
if (!definitions->len)
{
gchar *message = g_markup_escape_text (_("no usable field found"), -1);
g_ptr_array_add (definitions, g_strdup_printf ("&lt;%s&gt;", message));
g_free (message);
}
g_ptr_array_add (definitions, NULL);
ve->definition = g_strjoinv ("\n", (gchar **) definitions->pdata);
g_ptr_array_free (definitions, TRUE);
return ve;
}
static gint
view_entry_height (ViewEntry *ve, gint *word_offset, gint *defn_offset)
{
gint word_w = 0, word_h = 0;
gint defn_w = 0, defn_h = 0;
pango_layout_get_pixel_size (ve->word_layout, &word_w, &word_h);
pango_layout_get_pixel_size (ve->definition_layout, &defn_w, &defn_h);
// Align baselines, without further considerations
gint wb = pango_layout_get_baseline (ve->word_layout);
gint db = pango_layout_get_baseline (ve->definition_layout);
gint word_y = MAX (0, PANGO_PIXELS (db - wb));
gint defn_y = MAX (0, PANGO_PIXELS (wb - db));
if (word_offset)
*word_offset = word_y;
if (defn_offset)
*defn_offset = defn_y;
return MAX (word_y + word_h, defn_y + defn_h);
}
static GtkBorder
view_entry_get_padding (GtkStyleContext *style)
{
GtkBorder padding = {};
GtkStateFlags state = gtk_style_context_get_state (style);
gtk_style_context_get_padding (style, state, &padding);
return padding;
}
static gint
view_entry_draw (ViewEntry *ve, cairo_t *cr, gint full_width,
GtkStyleContext *style)
{
gint word_y = 0, defn_y = 0,
height = view_entry_height (ve, &word_y, &defn_y);
gtk_render_background (style, cr, 0, 0, full_width, height);
gtk_render_frame (style, cr, 0, 0, full_width, height);
// Top/bottom and left/right-dependent padding will not work, too much code
GtkBorder padding = view_entry_get_padding (style);
gtk_style_context_save (style);
gtk_style_context_add_class (style, GTK_STYLE_CLASS_RIGHT);
gtk_render_layout (style, cr,
full_width / 2 + padding.left, defn_y, ve->definition_layout);
gtk_style_context_restore (style);
gtk_style_context_save (style);
gtk_style_context_add_class (style, GTK_STYLE_CLASS_LEFT);
PangoLayoutIter *iter = pango_layout_get_iter (ve->definition_layout);
do
{
if (!pango_layout_iter_get_line_readonly (iter)->is_paragraph_start)
continue;
PangoRectangle logical = {};
pango_layout_iter_get_line_extents (iter, NULL, &logical);
gtk_render_layout (style, cr,
padding.left, word_y + PANGO_PIXELS (logical.y), ve->word_layout);
}
while (pango_layout_iter_next_line (iter));
pango_layout_iter_free (iter);
gtk_style_context_restore (style);
return height;
}
static void
view_entry_rebuild_layouts (ViewEntry *ve, GtkWidget *widget)
{
PangoContext *pc = gtk_widget_get_pango_context (widget);
GtkStyleContext *style = gtk_widget_get_style_context (widget);
gint full_width = gtk_widget_get_allocated_width (widget);
g_clear_object (&ve->word_layout);
g_clear_object (&ve->definition_layout);
GtkBorder padding = view_entry_get_padding (style);
gint part_width = full_width / 2 - padding.left - padding.right;
if (part_width < 1)
return;
// Left/right-dependent fonts aren't supported
ve->word_layout = pango_layout_new (pc);
pango_layout_set_text (ve->word_layout, ve->word, -1);
pango_layout_set_ellipsize (ve->word_layout, PANGO_ELLIPSIZE_END);
pango_layout_set_single_paragraph_mode (ve->word_layout, TRUE);
pango_layout_set_width (ve->word_layout, PANGO_SCALE * part_width);
// gtk_css_style_get_pango_attributes() is completely inaccessible,
// so the underline cannot be styled (GTK_STYLE_PROPERTY_FONT isn't enough)
PangoAttrList *attrs = pango_attr_list_new ();
PangoAttribute *u = pango_attr_underline_new (PANGO_UNDERLINE_SINGLE);
u->end_index = ve->word_matched;
pango_attr_list_insert (attrs, u);
pango_layout_set_attributes (ve->word_layout, attrs);
pango_attr_list_unref (attrs);
// TODO: preferably pre-validate the layout with pango_parse_markup(),
// so that it doesn't warn without indication on the frontend
ve->definition_layout = pango_layout_new (pc);
pango_layout_set_markup (ve->definition_layout, ve->definition, -1);
pango_layout_set_width (ve->definition_layout, PANGO_SCALE * part_width);
pango_layout_set_wrap (ve->definition_layout, PANGO_WRAP_WORD_CHAR);
}
// --- Widget ------------------------------------------------------------------
struct _StardictView
{
GtkWidget parent_instance;
StardictDict *dict; ///< The displayed dictionary
guint top_position; ///< Index of the topmost dict. entry
gchar *matched; ///< Highlight common word part of this
gint top_offset; ///< Pixel offset into the entry
// TODO: think about making it, e.g., a pair of (ViewEntry *, guint)
// NOTE: this is the index of a Pango paragraph (a virtual entity)
guint selected; ///< Offset to the selected definition
GList *entries; ///< ViewEntry-s within the view
};
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static ViewEntry *
make_entry (StardictView *self, StardictIterator *iterator)
{
const gchar *matched = self->matched ? self->matched : "";
ViewEntry *ve = view_entry_new (iterator, matched);
view_entry_rebuild_layouts (ve, GTK_WIDGET (self));
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return ve;
}
static void
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adjust_for_height (StardictView *self)
{
GtkWidget *widget = GTK_WIDGET (self);
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StardictIterator *iterator =
stardict_iterator_new (self->dict, self->top_position);
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gint missing = gtk_widget_get_allocated_height (widget) + self->top_offset;
for (GList *iter = self->entries, *next;
next = g_list_next (iter), iter; iter = next)
{
if (missing > 0)
missing -= view_entry_height (iter->data, NULL, NULL);
else
{
view_entry_destroy (iter->data);
self->entries = g_list_delete_link (self->entries, iter);
}
stardict_iterator_next (iterator);
}
GList *append = NULL;
while (missing > 0 && stardict_iterator_is_valid (iterator))
{
ViewEntry *ve = make_entry (self, iterator);
missing -= view_entry_height (ve, NULL, NULL);
append = g_list_prepend (append, ve);
stardict_iterator_next (iterator);
}
g_object_unref (iterator);
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self->entries = g_list_concat (self->entries, g_list_reverse (append));
gtk_widget_queue_draw (widget);
}
static void
adjust_for_offset (StardictView *self)
{
// If scrolled way up, prepend entries so long as it's possible
StardictIterator *iterator =
stardict_iterator_new (self->dict, self->top_position);
while (self->top_offset < 0)
{
stardict_iterator_prev (iterator);
if (!stardict_iterator_is_valid (iterator))
{
self->top_offset = 0;
break;
}
self->top_position = stardict_iterator_get_offset (iterator);
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ViewEntry *ve = make_entry (self, iterator);
self->top_offset += view_entry_height (ve, NULL, NULL);
self->entries = g_list_prepend (self->entries, ve);
}
g_object_unref (iterator);
// If scrolled way down, drop leading entries so long as it's possible
while (self->entries)
{
gint height = view_entry_height (self->entries->data, NULL, NULL);
if (self->top_offset < height)
break;
self->top_offset -= height;
view_entry_destroy (self->entries->data);
self->entries = g_list_delete_link (self->entries, self->entries);
self->top_position++;
}
if (self->top_offset && !self->entries)
self->top_offset = 0;
// Load replacement trailing entries, or drop those no longer visible
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adjust_for_height (self);
}
static void
reload (StardictView *self)
{
GtkWidget *widget = GTK_WIDGET (self);
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g_list_free_full (self->entries, (GDestroyNotify) view_entry_destroy);
self->entries = NULL;
gtk_widget_queue_draw (widget);
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if (gtk_widget_get_realized (widget) && self->dict)
adjust_for_height (self);
}
static gint
natural_row_size (GtkWidget *widget)
{
PangoLayout *layout = gtk_widget_create_pango_layout (widget, "X");
gint width = 0, height = 0;
pango_layout_get_pixel_size (layout, &width, &height);
g_object_unref (layout);
return height;
}
// --- Boilerplate -------------------------------------------------------------
G_DEFINE_TYPE (StardictView, stardict_view, GTK_TYPE_WIDGET)
static void
stardict_view_finalize (GObject *gobject)
{
StardictView *self = STARDICT_VIEW (gobject);
g_clear_object (&self->dict);
g_list_free_full (self->entries, (GDestroyNotify) view_entry_destroy);
self->entries = NULL;
g_free (self->matched);
self->matched = NULL;
G_OBJECT_CLASS (stardict_view_parent_class)->finalize (gobject);
}
static void
stardict_view_get_preferred_height (GtkWidget *widget,
gint *minimum, gint *natural)
{
// There isn't any value that would make any real sense
if (!STARDICT_VIEW (widget)->dict)
*natural = *minimum = 0;
else
*natural = *minimum = natural_row_size (widget);
}
static void
stardict_view_get_preferred_width (GtkWidget *widget,
gint *minimum, gint *natural)
{
GtkStyleContext *style = gtk_widget_get_style_context (widget);
GtkBorder padding = view_entry_get_padding (style);
*natural = *minimum = 2 * (padding.left + 1 * padding.right);
}
static void
stardict_view_realize (GtkWidget *widget)
{
GtkAllocation allocation;
gtk_widget_get_allocation (widget, &allocation);
GdkWindowAttr attributes =
{
.window_type = GDK_WINDOW_CHILD,
.x = allocation.x,
.y = allocation.y,
.width = allocation.width,
.height = allocation.height,
// Input-only would presumably also work (as in GtkPathBar, e.g.),
// but it merely seems to involve more work.
.wclass = GDK_INPUT_OUTPUT,
.visual = gtk_widget_get_visual (widget),
// GDK_SMOOTH_SCROLL_MASK is useless, will stop sending UP/DOWN
.event_mask = gtk_widget_get_events (widget) | GDK_SCROLL_MASK,
};
// We need this window to receive input events at all.
// TODO: see if we don't want GDK_WA_CURSOR for setting a text cursor
GdkWindow *window = gdk_window_new (gtk_widget_get_parent_window (widget),
&attributes, GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL);
// The default background colour of the GDK window is transparent
gtk_widget_register_window (widget, window);
gtk_widget_set_window (widget, window);
gtk_widget_set_realized (widget, TRUE);
}
static gboolean
stardict_view_draw (GtkWidget *widget, cairo_t *cr)
{
StardictView *self = STARDICT_VIEW (widget);
GtkAllocation allocation;
gtk_widget_get_allocation (widget, &allocation);
GtkStyleContext *style = gtk_widget_get_style_context (widget);
gtk_render_background (style, cr,
0, 0, allocation.width, allocation.height);
gtk_render_frame (style, cr,
0, 0, allocation.width, allocation.height);
gint offset = -self->top_offset;
gint i = self->top_position;
for (GList *iter = self->entries; iter; iter = iter->next)
{
// Style regions would be appropriate, if they weren't deprecated.
// GTK+ CSS gadgets/nodes are an internal API. We don't want to turn
// this widget into a container, to avoid needless complexity.
//
// gtk_style_context_{get,set}_path() may be misused by adding the same
// GType with gtk_widget_path_append_type() and changing its name
// using gtk_widget_path_iter_set_name()... but that is ugly.
gtk_style_context_save (style);
gtk_style_context_add_class (style, (i++ & 1) ? "even" : "odd");
cairo_save (cr);
cairo_translate (cr, 0, offset);
// TODO: later exclude clipped entries, but it's not that important
offset += view_entry_draw (iter->data, cr, allocation.width, style);
cairo_restore (cr);
gtk_style_context_restore (style);
}
return TRUE;
}
static void
stardict_view_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
{
GTK_WIDGET_CLASS (stardict_view_parent_class)
->size_allocate (widget, allocation);
reload (STARDICT_VIEW (widget));
}
static void
stardict_view_screen_changed (GtkWidget *widget, G_GNUC_UNUSED GdkScreen *prev)
{
// Update the minimum size
gtk_widget_queue_resize (widget);
// Recreate Pango layouts
reload (STARDICT_VIEW (widget));
}
static gboolean
stardict_view_scroll_event (GtkWidget *widget, GdkEventScroll *event)
{
// TODO: rethink the notes here to rather iterate over /definition lines/
// - iterate over selected lines, maybe one, maybe three
StardictView *self = STARDICT_VIEW (widget);
if (!self->dict)
return FALSE;
switch (event->direction)
{
case GDK_SCROLL_UP:
stardict_view_scroll (self, GTK_SCROLL_STEPS, -3);
return TRUE;
case GDK_SCROLL_DOWN:
stardict_view_scroll (self, GTK_SCROLL_STEPS, +3);
return TRUE;
case GDK_SCROLL_SMOOTH:
self->top_offset += event->delta_y;
adjust_for_offset (self);
return TRUE;
default:
return FALSE;
}
}
static void
stardict_view_class_init (StardictViewClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = stardict_view_finalize;
// TODO: handle mouse events for text selection
// See https://wiki.gnome.org/HowDoI/CustomWidgets for some guidelines.
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
widget_class->get_preferred_height = stardict_view_get_preferred_height;
widget_class->get_preferred_width = stardict_view_get_preferred_width;
widget_class->realize = stardict_view_realize;
widget_class->draw = stardict_view_draw;
widget_class->size_allocate = stardict_view_size_allocate;
widget_class->screen_changed = stardict_view_screen_changed;
widget_class->scroll_event = stardict_view_scroll_event;
gtk_widget_class_set_css_name (widget_class, "stardict-view");
}
static void
stardict_view_init (G_GNUC_UNUSED StardictView *self)
{
}
// --- Public ------------------------------------------------------------------
GtkWidget *
stardict_view_new (void)
{
return GTK_WIDGET (g_object_new (STARDICT_TYPE_VIEW, NULL));
}
void
stardict_view_set_position (StardictView *self,
StardictDict *dict, guint position)
{
g_return_if_fail (STARDICT_IS_VIEW (self));
g_return_if_fail (STARDICT_IS_DICT (dict));
// Update the minimum size, if appropriate (almost never)
if (!self->dict != !dict)
gtk_widget_queue_resize (GTK_WIDGET (self));
g_clear_object (&self->dict);
self->dict = g_object_ref (dict);
self->top_position = position;
self->top_offset = 0;
reload (self);
}
void
stardict_view_set_matched (StardictView *self, const gchar *matched)
{
g_return_if_fail (STARDICT_IS_VIEW (self));
g_free (self->matched);
self->matched = g_strdup (matched);
reload (self);
}
void
stardict_view_scroll (StardictView *self, GtkScrollStep step, gdouble amount)
{
g_return_if_fail (STARDICT_IS_VIEW (self));
GtkWidget *widget = GTK_WIDGET (self);
switch (step)
{
case GTK_SCROLL_STEPS:
self->top_offset += amount * natural_row_size (widget);
break;
case GTK_SCROLL_PAGES:
self->top_offset += amount * gtk_widget_get_allocated_height (widget);
break;
default:
break;
}
adjust_for_offset (self);
}