sdgui: support text selection in the view

This is generally an improvement over the initial GtkLabel approach:
 - Multiple definition lines can be selected at once.
 - The widget doesn't keep a selection caret around (which means
   it can't be controlled from the keyboard, a conscious trade-off).
 - Text doesn't needlessly go to PRIMARY immediately during selection,
   making it somewhat possible lift the self-exception for
   the PRIMARY selection watch.

Closes #2
This commit is contained in:
Přemysl Eric Janouch 2022-08-02 03:04:46 +02:00
parent 5ed881d25b
commit 2ff01f9fdb
Signed by: p
GPG Key ID: A0420B94F92B9493
3 changed files with 409 additions and 37 deletions

View File

@ -3,9 +3,9 @@ project (sdtui VERSION 0.1.0 LANGUAGES C)
# Moar warnings
if ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU" OR CMAKE_COMPILER_IS_GNUCC)
set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99")
set (CMAKE_C_FLAGS_DEBUG
"${CMAKE_C_FLAGS_DEBUG} -Wall -Wextra -Wno-missing-field-initializers")
set (ignores "-Wno-missing-field-initializers -Wno-cast-function-type")
set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99 ${ignores}")
set (CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -Wall -Wextra")
endif ()
# For custom modules

View File

@ -454,7 +454,10 @@ main (int argc, char *argv[])
"stardict-view.even:backdrop {"
"background: mix(@theme_unfocused_base_color, "
"@theme_fg_color, 0.03); "
"color: @theme_fg_color; /* should be more faded than 'text' */ }";
"color: @theme_fg_color; /* should be more faded than 'text' */ }"
"stardict-view:selected {"
"background-color: @theme_selected_bg_color; "
"color: @theme_selected_fg_color; }";
GdkScreen *screen = gdk_screen_get_default ();
GtkCssProvider *provider = gtk_css_provider_new ();

View File

@ -1,7 +1,7 @@
/*
* StarDict GTK+ UI - dictionary view component
*
* Copyright (c) 2021, Přemysl Eric Janouch <p@janouch.name>
* Copyright (c) 2021 - 2022, 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.
@ -135,27 +135,69 @@ view_entry_get_padding (GtkStyleContext *style)
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);
typedef struct view_entry_render_ctx ViewEntryRenderCtx;
gtk_render_background (style, cr, 0, 0, full_width, height);
gtk_render_frame (style, cr, 0, 0, full_width, height);
// TODO: see if we can't think of a cleaner way of doing this
struct view_entry_render_ctx
{
GtkStyleContext *style;
cairo_t *cr;
int width;
int height;
// Forwarded from StardictView
PangoLayout *selection_layout;
int selection_begin;
int selection_end;
};
static void
view_entry_render (ViewEntryRenderCtx *ctx, gdouble x, gdouble y,
PangoLayout *layout)
{
gtk_render_layout (ctx->style, ctx->cr, x, y, layout);
if (layout != ctx->selection_layout)
return;
gtk_style_context_save (ctx->style);
gtk_style_context_set_state (ctx->style, GTK_STATE_FLAG_SELECTED);
cairo_save (ctx->cr);
int ranges[2] = { MIN (ctx->selection_begin, ctx->selection_end),
MAX (ctx->selection_begin, ctx->selection_end) };
cairo_region_t *region
= gdk_pango_layout_get_clip_region (layout, x, y, ranges, 1);
gdk_cairo_region (ctx->cr, region);
cairo_clip (ctx->cr);
cairo_region_destroy (region);
gtk_render_background (ctx->style, ctx->cr, 0, 0, ctx->width, ctx->height);
gtk_render_layout (ctx->style, ctx->cr, x, y, layout);
cairo_restore (ctx->cr);
gtk_style_context_restore (ctx->style);
}
static gint
view_entry_draw (ViewEntry *ve, ViewEntryRenderCtx *ctx)
{
gint word_y = 0, defn_y = 0;
ctx->height = view_entry_height (ve, &word_y, &defn_y);
gtk_render_background (ctx->style, ctx->cr, 0, 0, ctx->width, ctx->height);
gtk_render_frame (ctx->style, ctx->cr, 0, 0, ctx->width, ctx->height);
// Top/bottom and left/right-dependent padding will not work, too much code
GtkBorder padding = view_entry_get_padding (style);
GtkBorder padding = view_entry_get_padding (ctx->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 (ctx->style);
gtk_style_context_add_class (ctx->style, GTK_STYLE_CLASS_RIGHT);
view_entry_render (ctx, ctx->width / 2 + padding.left, defn_y,
ve->definition_layout);
gtk_style_context_restore (ctx->style);
gtk_style_context_save (style);
gtk_style_context_add_class (style, GTK_STYLE_CLASS_LEFT);
gtk_style_context_save (ctx->style);
gtk_style_context_add_class (ctx->style, GTK_STYLE_CLASS_LEFT);
PangoLayoutIter *iter = pango_layout_get_iter (ve->definition_layout);
do
{
@ -164,13 +206,13 @@ view_entry_draw (ViewEntry *ve, cairo_t *cr, gint full_width,
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);
view_entry_render (ctx, 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;
gtk_style_context_restore (ctx->style);
return ctx->height;
}
static void
@ -224,10 +266,12 @@ struct _StardictView
gint top_offset; ///< Pixel offset into the entry
gdouble drag_last_offset; ///< Last offset when dragging
// 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
GtkGesture *selection_gesture; ///< Selection gesture
GWeakRef selection; ///< Selected PangoLayout, if any
int selection_begin; ///< Start index within `selection`
int selection_end; ///< End index within `selection`
};
static ViewEntry *
@ -321,10 +365,14 @@ reload (StardictView *self)
{
GtkWidget *widget = GTK_WIDGET (self);
// FIXME: this invalidates the selection, we'd need better identification
g_list_free_full (self->entries, (GDestroyNotify) view_entry_destroy);
self->entries = NULL;
gtk_widget_queue_draw (widget);
// For consistency, and the check in make_context_menu()
self->selection_begin = self->selection_end = -1;
if (gtk_widget_get_realized (widget) && self->dict)
adjust_for_height (self);
}
@ -352,6 +400,9 @@ stardict_view_finalize (GObject *gobject)
g_list_free_full (self->entries, (GDestroyNotify) view_entry_destroy);
self->entries = NULL;
g_object_unref (self->selection_gesture);
g_weak_ref_clear (&self->selection);
g_free (self->matched);
self->matched = NULL;
@ -397,7 +448,7 @@ stardict_view_realize (GtkWidget *widget)
.wclass = GDK_INPUT_OUTPUT,
.visual = gtk_widget_get_visual (widget),
.event_mask = gtk_widget_get_events (widget) | GDK_SCROLL_MASK
| GDK_SMOOTH_SCROLL_MASK,
| GDK_SMOOTH_SCROLL_MASK | GDK_BUTTON_PRESS_MASK,
};
// We need this window to receive input events at all.
@ -425,6 +476,17 @@ stardict_view_draw (GtkWidget *widget, cairo_t *cr)
gtk_render_frame (style, cr,
0, 0, allocation.width, allocation.height);
ViewEntryRenderCtx ctx =
{
.style = style,
.cr = cr,
.width = allocation.width,
.height = 0,
.selection_layout = g_weak_ref_get (&self->selection),
.selection_begin = self->selection_begin,
.selection_end = self->selection_end,
};
gint offset = -self->top_offset;
gint i = self->top_position;
for (GList *iter = self->entries; iter; iter = iter->next)
@ -442,14 +504,86 @@ stardict_view_draw (GtkWidget *widget, cairo_t *cr)
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);
offset += view_entry_draw (iter->data, &ctx);
cairo_restore (cr);
gtk_style_context_restore (style);
}
g_clear_object (&ctx.selection_layout);
return TRUE;
}
/// Figure out which layout is at given widget coordinates, and translate them.
static PangoLayout *
layout_at (StardictView *self, int *x, int *y)
{
GtkWidget *widget = GTK_WIDGET (self);
int width = gtk_widget_get_allocated_width (widget);
// The algorithm here is a simplification of stardict_view_draw().
GtkStyleContext *style = gtk_widget_get_style_context (widget);
GtkBorder padding = view_entry_get_padding (style);
gint offset = -self->top_offset;
for (GList *iter = self->entries; iter; iter = iter->next)
{
ViewEntry *ve = iter->data;
if (G_UNLIKELY (*y < offset))
break;
gint top_y = offset, word_y = 0, defn_y = 0;
offset += view_entry_height (ve, &word_y, &defn_y);
if (*y >= offset)
continue;
if (*x >= width / 2)
{
*x -= width / 2 + padding.left;
*y -= top_y + defn_y;
return ve->definition_layout;
}
else
{
*x -= padding.left;
*y -= top_y + word_y;
return ve->word_layout;
}
}
return NULL;
}
/// Figure out a layout's coordinates.
static gboolean
layout_coords (StardictView *self, PangoLayout *layout, int *x, int *y)
{
GtkWidget *widget = GTK_WIDGET (self);
int width = gtk_widget_get_allocated_width (widget);
// The algorithm here is a simplification of stardict_view_draw().
GtkStyleContext *style = gtk_widget_get_style_context (widget);
GtkBorder padding = view_entry_get_padding (style);
gint offset = -self->top_offset;
for (GList *iter = self->entries; iter; iter = iter->next)
{
ViewEntry *ve = iter->data;
gint top_y = offset, word_y = 0, defn_y = 0;
offset += view_entry_height (ve, &word_y, &defn_y);
if (layout == ve->definition_layout)
{
*x = width / 2 + padding.left;
*y = top_y + defn_y;
return TRUE;
}
if (layout == ve->word_layout)
{
*x = padding.left;
*y = top_y + word_y;
return TRUE;
}
}
return FALSE;
}
static void
stardict_view_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
{
@ -501,6 +635,150 @@ stardict_view_scroll_event (GtkWidget *widget, GdkEventScroll *event)
}
}
static int
layout_index_at (PangoLayout *layout, int x, int y)
{
int index = 0, trailing = 0;
(void) pango_layout_xy_to_index (layout,
x * PANGO_SCALE,
y * PANGO_SCALE,
&index,
&trailing);
const char *text = pango_layout_get_text (layout) + index;
while (trailing--)
{
int len = g_utf8_next_char(text) - text;
text += len;
index += len;
}
return index;
}
static void
publish_selection (StardictView *self, GdkAtom target)
{
PangoLayout *layout = g_weak_ref_get (&self->selection);
if (!layout || self->selection_begin == self->selection_end)
return;
// Unlike GtkLabel, we don't place the selection in PRIMARY immediately.
const char *text = pango_layout_get_text (layout);
int len = strlen (text),
s1 = MIN (self->selection_begin, self->selection_end),
s2 = MAX (self->selection_begin, self->selection_end);
if (s1 >= 0 && s1 <= len && s2 >= 0 && s2 <= len)
gtk_clipboard_set_text (gtk_clipboard_get (target), text + s1, s2 - s1);
g_object_unref (layout);
}
static void
select_word_at (StardictView *self, int x, int y)
{
PangoLayout *layout = layout_at (self, &x, &y);
if (!layout)
return;
const char *text = pango_layout_get_text (layout), *p = NULL;
const char *begin = text + layout_index_at (layout, x, y), *end = begin;
while ((p = g_utf8_find_prev_char (text, begin))
&& !g_unichar_isspace (g_utf8_get_char (p)))
begin = p;
gunichar c;
while ((c = g_utf8_get_char (end)) && !g_unichar_isspace (c))
end = g_utf8_next_char (end);
g_weak_ref_set (&self->selection, layout);
self->selection_begin = begin - text;
self->selection_end = end - text;
gtk_widget_queue_draw (GTK_WIDGET (self));
publish_selection (self, GDK_SELECTION_PRIMARY);
}
static void
select_all_at (StardictView *self, int x, int y)
{
PangoLayout *layout = layout_at (self, &x, &y);
if (!layout)
return;
g_weak_ref_set (&self->selection, layout);
self->selection_begin = 0;
self->selection_end = strlen (pango_layout_get_text (layout));
gtk_widget_queue_draw (GTK_WIDGET (self));
publish_selection (self, GDK_SELECTION_PRIMARY);
}
static void
on_copy_activate (G_GNUC_UNUSED GtkMenuItem *item, gpointer user_data)
{
publish_selection (STARDICT_VIEW (user_data), GDK_SELECTION_CLIPBOARD);
}
static gboolean
destroy_widget_idle_source_func (GtkWidget *widget)
{
// The whole menu is deactivated /before/ any item is activated,
// and a destroyed child item will not activate.
gtk_widget_destroy (widget);
return FALSE;
}
static GtkMenu *
make_context_menu (StardictView *self)
{
GtkWidget *copy = gtk_menu_item_new_with_mnemonic ("_Copy");
gtk_widget_set_sensitive (copy,
self->selection_begin < self->selection_end);
g_signal_connect_data (copy, "activate",
G_CALLBACK (on_copy_activate), g_object_ref (self),
(GClosureNotify) g_object_unref, 0);
GtkWidget *menu = gtk_menu_new ();
gtk_menu_shell_append (GTK_MENU_SHELL (menu), copy);
// As per GTK+ 3 Common Questions, 1.5.
g_object_ref_sink (menu);
g_signal_connect_swapped (menu, "deactivate",
G_CALLBACK (g_idle_add), destroy_widget_idle_source_func);
g_signal_connect (menu, "destroy",
G_CALLBACK (g_object_unref), NULL);
gtk_widget_show_all (menu);
return GTK_MENU (menu);
}
static gboolean
stardict_view_button_press_event (GtkWidget *widget, GdkEventButton *event)
{
StardictView *self = STARDICT_VIEW (widget);
if (gdk_event_triggers_context_menu((const GdkEvent *) event))
{
gtk_menu_popup_at_pointer (make_context_menu (self),
(const GdkEvent *) event);
return GDK_EVENT_STOP;
}
if (event->type == GDK_2BUTTON_PRESS && event->button == GDK_BUTTON_PRIMARY)
{
gtk_event_controller_reset (
GTK_EVENT_CONTROLLER (self->selection_gesture));
select_word_at (self, event->x, event->y);
return GDK_EVENT_STOP;
}
if (event->type == GDK_3BUTTON_PRESS && event->button == GDK_BUTTON_PRIMARY)
{
gtk_event_controller_reset (
GTK_EVENT_CONTROLLER (self->selection_gesture));
select_all_at (self, event->x, event->y);
return GDK_EVENT_STOP;
}
return GTK_WIDGET_CLASS (stardict_view_parent_class)
->button_press_event (widget, event);
}
static void
on_drag_begin (GtkGestureDrag *drag, G_GNUC_UNUSED gdouble start_x,
G_GNUC_UNUSED gdouble start_y, gpointer user_data)
@ -511,7 +789,7 @@ on_drag_begin (GtkGestureDrag *drag, G_GNUC_UNUSED gdouble start_x,
GdkModifierType state = 0;
const GdkEvent *last_event = gtk_gesture_get_last_event (gesture, sequence);
gdk_event_get_state (last_event, &state);
(void) gdk_event_get_state (last_event, &state);
if (state & gtk_accelerator_get_default_mod_mask ())
gtk_gesture_set_sequence_state (gesture, sequence,
GTK_EVENT_SEQUENCE_DENIED);
@ -533,14 +811,87 @@ on_drag_update (G_GNUC_UNUSED GtkGestureDrag *drag,
self->drag_last_offset = offset_y;
}
static void
on_select_begin (GtkGestureDrag *drag, gdouble start_x, gdouble start_y,
gpointer user_data)
{
// Despite our two gestures not being grouped up, claiming one doesn't
// deny the other, and :exclusive isn't the opposite of :touch-only.
// A non-NULL sequence indicates a touch event.
GtkGesture *gesture = GTK_GESTURE (drag);
if (gtk_gesture_get_last_updated_sequence (gesture))
{
gtk_gesture_set_state(gesture, GTK_EVENT_SEQUENCE_DENIED);
return;
}
StardictView *self = STARDICT_VIEW (user_data);
g_weak_ref_set (&self->selection, NULL);
self->selection_begin = -1;
self->selection_end = -1;
gtk_widget_queue_draw (GTK_WIDGET (self));
int layout_x = start_x, layout_y = start_y;
PangoLayout *layout = layout_at (self, &layout_x, &layout_y);
if (!layout)
{
gtk_gesture_set_state(gesture, GTK_EVENT_SEQUENCE_DENIED);
return;
}
g_weak_ref_set (&self->selection, layout);
self->selection_end = self->selection_begin
= layout_index_at (layout, layout_x, layout_y);
gtk_gesture_set_state (gesture, GTK_EVENT_SEQUENCE_CLAIMED);
}
static void
on_select_update (GtkGestureDrag *drag, gdouble offset_x, gdouble offset_y,
gpointer user_data)
{
GtkGesture *gesture = GTK_GESTURE (drag);
StardictView *self = STARDICT_VIEW (user_data);
PangoLayout *layout = g_weak_ref_get (&self->selection);
if (!layout)
{
gtk_gesture_set_state(gesture, GTK_EVENT_SEQUENCE_DENIED);
return;
}
double start_x = 0, start_y = 0;
(void) gtk_gesture_drag_get_start_point (drag, &start_x, &start_y);
int x = 0, y = 0;
if (!layout_coords (self, layout, &x, &y))
{
g_warning ("internal error: weakly referenced layout not found");
gtk_gesture_set_state(gesture, GTK_EVENT_SEQUENCE_DENIED);
goto out;
}
self->selection_end = layout_index_at (layout,
start_x + offset_x - x,
start_y + offset_y - y);
gtk_widget_queue_draw (GTK_WIDGET (self));
out:
g_object_unref (layout);
}
static void
on_select_end (G_GNUC_UNUSED GtkGestureDrag *drag,
G_GNUC_UNUSED gdouble offset_x, G_GNUC_UNUSED gdouble offset_y,
gpointer user_data)
{
publish_selection (STARDICT_VIEW (user_data), GDK_SELECTION_PRIMARY);
}
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;
@ -549,22 +900,40 @@ stardict_view_class_init (StardictViewClass *klass)
widget_class->size_allocate = stardict_view_size_allocate;
widget_class->screen_changed = stardict_view_screen_changed;
widget_class->scroll_event = stardict_view_scroll_event;
widget_class->button_press_event = stardict_view_button_press_event;
gtk_widget_class_set_css_name (widget_class, "stardict-view");
}
static void
stardict_view_init (G_GNUC_UNUSED StardictView *self)
stardict_view_init (StardictView *self)
{
g_weak_ref_init (&self->selection, NULL);
self->selection_begin = -1;
self->selection_end = -1;
GtkGesture *drag = gtk_gesture_drag_new (GTK_WIDGET (self));
gtk_gesture_single_set_touch_only (GTK_GESTURE_SINGLE (drag), TRUE);
gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (drag),
GTK_PHASE_BUBBLE);
GTK_PHASE_TARGET);
g_object_set_data_full (G_OBJECT (self), "stardict-view-drag-gesture",
drag, g_object_unref);
g_signal_connect (drag, "drag-begin",
G_CALLBACK (on_drag_begin), self);
g_signal_connect (drag, "drag-update",
G_CALLBACK (on_drag_update), self);
g_signal_connect (drag, "drag-begin", G_CALLBACK (on_drag_begin), self);
g_signal_connect (drag, "drag-update", G_CALLBACK (on_drag_update), self);
self->selection_gesture = gtk_gesture_drag_new (GTK_WIDGET (self));
gtk_gesture_single_set_exclusive (
GTK_GESTURE_SINGLE (self->selection_gesture), TRUE);
gtk_event_controller_set_propagation_phase (
GTK_EVENT_CONTROLLER (self->selection_gesture), GTK_PHASE_TARGET);
g_signal_connect (self->selection_gesture, "drag-begin",
G_CALLBACK (on_select_begin), self);
g_signal_connect (self->selection_gesture, "drag-update",
G_CALLBACK (on_select_update), self);
g_signal_connect (self->selection_gesture, "drag-end",
G_CALLBACK (on_select_end), self);
}
// --- Public ------------------------------------------------------------------