SharpMuPDF/mupdf/platform/gl/gl-form.c

// Copyright (C) 2004-2024 Artifex Software, Inc.
//
// This file is part of MuPDF.
//
// MuPDF is free software: you can redistribute it and/or modify it under the
// terms of the GNU Affero General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// MuPDF 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 Affero General Public License for more
// details.
//
// You should have received a copy of the GNU Affero General Public License
// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
//
// Alternative licensing terms are available from the licensor.
// For commercial licensing, see <https://www.artifex.com/> or contact
// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
// CA 94129, USA, for further information.

#include "gl-app.h"

#include <string.h>
#include <stdio.h>

#include "mupdf/helpers/pkcs7-openssl.h"

static pdf_annot *sig_widget;
static char *sig_distinguished_name = NULL;
static pdf_signature_error sig_cert_error;
static pdf_signature_error sig_digest_error;
static int sig_valid_until;
static int sig_readonly;

static char cert_filename[PATH_MAX];
static struct input cert_password;

static int sign_flags = PDF_SIGNATURE_DEFAULT_APPEARANCE;
static struct input sign_reason_input;
static int sign_reason_input_initialised = 0;
static struct input sign_location_input;
static int sign_location_input_initialised = 0;
static char sign_image_filename[PATH_MAX];
static fz_image *sign_image = NULL;

static struct texture preview_tex = { 0 };
static int preview_needs_update = 0;

static void trace_field_value(pdf_annot *annot, const char *set_value)
{
	const char *get_value = pdf_annot_field_value(ctx, annot);
	trace_action("print('Set field %d:', repr(%q), repr(%q));\n", pdf_to_num(ctx, pdf_annot_obj(ctx, annot)), set_value, get_value);
}

int do_sign(void)
{
	pdf_pkcs7_signer *signer = NULL;
	int ok = 1;
	int labels = sign_flags & PDF_SIGNATURE_SHOW_LABELS;
	int graphic_name = sign_flags & PDF_SIGNATURE_SHOW_GRAPHIC_NAME;
	int text_name = sign_flags & PDF_SIGNATURE_SHOW_TEXT_NAME;
	int dn = sign_flags & PDF_SIGNATURE_SHOW_DN;
	int date = sign_flags & PDF_SIGNATURE_SHOW_DATE;
	int logo = sign_flags & PDF_SIGNATURE_SHOW_LOGO;

	fz_var(signer);

	fz_try(ctx)
	{
		trace_action("widget.sign(new PDFPKCS7Signer(%q, %q), {", cert_filename, cert_password.text);

		trace_action("'showLabels':%s,", labels ? "true" : "false");
		trace_action("'showDN':%s,", dn ? "true" : "false");
		trace_action("'showDate':%s,", date ? "true" : "false");
		trace_action("'showTextName':%s,", text_name ? "true" : "false");
		trace_action("'showGraphicName':%s,", graphic_name ? "true" : "false");
		trace_action("'showLogo':%s}, ", logo ? "true" : "false");

		if (strlen(sign_image_filename) > 0)
			trace_action("new Image(%q, null), ", sign_image_filename);
		else
			trace_action("null, ");

		if (strlen(sign_reason_input.text) > 0)
			trace_action("%q, ", sign_reason_input.text);
		else
			trace_action("null, ");

		if (strlen(sign_location_input.text) > 0)
			trace_action("%q);\n", sign_location_input.text);
		else
			trace_action("null);\n");

		signer = pkcs7_openssl_read_pfx(ctx, cert_filename, cert_password.text);
		pdf_sign_signature(ctx, sig_widget, signer, sign_flags, sign_image, sign_reason_input.text, sign_location_input.text);
		ui_show_warning_dialog("Signed document successfully.");
	}
	fz_always(ctx)
	{
		pdf_drop_signer(ctx, signer);
		fz_drop_image(ctx, sign_image);
		sign_image = NULL;
	}
	fz_catch(ctx)
	{
		ui_show_warning_dialog("%s", fz_caught_message(ctx));
		fz_report_error(ctx);
		ok = 0;
	}
	return ok;
}

static void do_clear_signature(void)
{
	fz_try(ctx)
	{
		trace_action("widget.clearSignature();\n");
		pdf_clear_signature(ctx, sig_widget);
		ui_show_warning_dialog("Signature cleared successfully.");
	}
	fz_catch(ctx)
	{
		ui_show_warning_dialog("%s", fz_caught_message(ctx));
		fz_report_error(ctx);
	}
}

static int image_file_filter(const char *fn)
{
	return !!strstr(fn, ".jpg") || !!strstr(fn, ".jpeg") || !!strstr(fn, ".png");
}

static void signature_appearance_dialog(void);

static void signature_select_image_dialog(void)
{
	if (ui_open_file(sign_image_filename, "Select an image for use in signature:"))
	{
		if (sign_image_filename[0] != 0)
		{
			fz_try(ctx)
			{
				sign_image = fz_new_image_from_file(ctx, sign_image_filename);
				sign_flags &= ~PDF_SIGNATURE_SHOW_GRAPHIC_NAME;
				preview_needs_update = 1;
			}
			fz_catch(ctx)
			{
				ui_show_warning_dialog("%s", fz_caught_message(ctx));
				fz_report_error(ctx);
				ui.dialog = signature_select_image_dialog;
			}
		}

		ui.dialog = signature_appearance_dialog;
	}
}


static void signature_appearance_init(void)
{
	if (!sign_reason_input_initialised)
	{
		ui_input_init(&sign_reason_input, "");
		sign_reason_input_initialised = 1;
	}
	if (!sign_location_input_initialised)
	{
		ui_input_init(&sign_location_input, "");
		sign_location_input_initialised = 1;
	}
	preview_needs_update = 1;
}

static void signature_appearance_dialog(void)
{
	ui_dialog_begin(ui.gridsize*16, (ui.gridsize+4)*16);
	{
		int orig_flags = sign_flags;
		int labels = sign_flags & PDF_SIGNATURE_SHOW_LABELS;
		int graphic_name = sign_flags & PDF_SIGNATURE_SHOW_GRAPHIC_NAME;
		int graphic_image = sign_image != NULL;
		int text_name = sign_flags & PDF_SIGNATURE_SHOW_TEXT_NAME;
		int dn = sign_flags & PDF_SIGNATURE_SHOW_DN;
		int date = sign_flags & PDF_SIGNATURE_SHOW_DATE;
		int logo = sign_flags & PDF_SIGNATURE_SHOW_LOGO;
		fz_irect preview_rect;

		ui_layout(T, X, NW, ui.padsize*2, ui.padsize);

		{
			ui_panel_begin(0, ui.gridsize * 6, 0, 0, 0);
			ui_layout(T, Y, NW, 0, 0);

			ui_label("Preview:");
			ui_spacer();

			ui_layout(ALL, BOTH, CENTER, 0, 0);
			preview_rect = ui_pack(0, 0);

			ui_panel_end();
		}

		ui_spacer();

		{
			ui_label("Graphic:");
			ui_checkbox("Name", &graphic_name);

			ui_panel_begin(ui.gridsize * 10, ui.gridsize, 0, 0, 0);
			ui_layout(L, X, NW, 0, 0);
			ui_checkbox("Image", &graphic_image);

			ui_spacer();

			if (ui_button("Select image"))
			{
				fz_drop_image(ctx, sign_image);
				sign_image = NULL;
				ui_init_open_file(".", image_file_filter);
				ui.dialog = signature_select_image_dialog;
			}
			ui_panel_end();

			if (graphic_name && graphic_image)
			{
				fz_drop_image(ctx, sign_image);
				sign_image = NULL;
				graphic_image = 0;
			}
		}

		ui_spacer();

		{
			ui_label("Text:");

			ui_panel_begin(0, ui.gridsize * 5, 0, 0, 0);
			{
				ui_layout(L, Y, NW, 0, 0);

				ui_panel_begin(ui.gridsize * 7, ui.gridsize * 5, 0, 0, 0);
				{
					ui_layout(T, Y, NW, 0, 0);
					ui_checkbox("Labels", &labels);
					ui_checkbox("Common name", &text_name);
					ui_checkbox("Distinguished name", &dn);
					ui_checkbox("Date", &date);
					ui_checkbox("Logo", &logo);
				}
				ui_panel_end();

				ui_panel_begin(ui.gridsize * 5, ui.gridsize * 5, 0, 0, 0);
				{
					ui_layout(T, Y, NW, 0, 0);

					ui_panel_begin(ui.gridsize * 5, ui.gridsize, 0, 0, 0);
					ui_layout(L, X, NW, 0, 0);
					ui_label("Reason:");
					ui_spacer();
					if (ui_input(&sign_reason_input, ui.gridsize * 5, 1))
						preview_needs_update = 1;
					ui_panel_end();

					ui_panel_begin(ui.gridsize * 10, ui.gridsize, 0, 0, 0);
					ui_layout(L, X, NW, 0, 0);
					ui_label("Location:");
					ui_spacer();
					if (ui_input(&sign_location_input, ui.gridsize * 5, 1))
						preview_needs_update = 1;
					ui_panel_end();
				}
				ui_panel_end();
			}
			ui_panel_end();

			if (!text_name && !dn && !date && !strlen(sign_reason_input.text) && !strlen(sign_location_input.text))
			{
				labels = 1;
				text_name = 1;
			}
		}

		sign_flags = 0;
		sign_flags |= labels ? PDF_SIGNATURE_SHOW_LABELS : 0;
		sign_flags |= dn ? PDF_SIGNATURE_SHOW_DN : 0;
		sign_flags |= date ? PDF_SIGNATURE_SHOW_DATE : 0;
		sign_flags |= text_name ? PDF_SIGNATURE_SHOW_TEXT_NAME : 0;
		sign_flags |= graphic_name ? PDF_SIGNATURE_SHOW_GRAPHIC_NAME : 0;
		sign_flags |= logo ? PDF_SIGNATURE_SHOW_LOGO : 0;

		if (orig_flags != sign_flags)
			preview_needs_update = 1;

		if (preview_needs_update)
		{
			fz_pixmap *pix;
			pdf_pkcs7_signer *signer;
			int w = preview_rect.x1 - preview_rect.x0;
			int h = preview_rect.y1 - preview_rect.y0;

			signer = pkcs7_openssl_read_pfx(ctx, cert_filename, cert_password.text);
			pix = pdf_preview_signature_as_pixmap(ctx,
				w, h, FZ_LANG_UNSET, signer, sign_flags, sign_image,
				strlen(sign_reason_input.text) ? sign_reason_input.text : NULL,
				strlen(sign_location_input.text) ? sign_location_input.text : NULL);
			pdf_drop_signer(ctx, signer);
			ui_texture_from_pixmap(&preview_tex, pix);
			fz_drop_pixmap(ctx, pix);

			preview_needs_update = 0;
		}

		ui_draw_image(&preview_tex, preview_rect.x0, preview_rect.y0);

		ui_layout(B, X, NW, ui.padsize, ui.padsize);
		ui_panel_begin(0, ui.gridsize, 0, 0, 0);
		{
			ui_layout(R, NONE, S, 0, 0);
			if (ui_button("Cancel"))
			{
				fz_drop_image(ctx, sign_image);
				sign_image = NULL;
				ui.dialog = NULL;
			}
			ui_spacer();
			if (ui_button("Okay"))
			{
				ui.dialog = NULL;
				do_save_signed_pdf_file();
			}
		}
		ui_panel_end();
	}
	ui_dialog_end();
}

static int is_valid_certificate_and_password(void)
{
	fz_try(ctx)
	{
		pdf_pkcs7_signer *signer = pkcs7_openssl_read_pfx(ctx, cert_filename, cert_password.text);
		pdf_drop_signer(ctx, signer);
	}
	fz_catch(ctx)
		return 0;
	return 1;
}

static void cert_password_dialog(void)
{
	int is;
	ui_dialog_begin(ui.gridsize*16, (ui.gridsize+4)*3);
	{
		ui_layout(T, X, NW, ui.padsize, ui.padsize);
		ui_label("Password:");
		is = ui_input(&cert_password, 200, 1);

		ui_layout(B, X, NW, ui.padsize, ui.padsize);
		ui_panel_begin(0, ui.gridsize, 0, 0, 0);
		{
			ui_layout(R, NONE, S, 0, 0);
			if (ui_button("Cancel"))
				ui.dialog = NULL;
			ui_spacer();
			if (ui_button("Okay") || is == UI_INPUT_ACCEPT)
			{
				if (is_valid_certificate_and_password()) {
					signature_appearance_init();
					ui.dialog = signature_appearance_dialog;
				} else {
					ui_show_warning_dialog("%s", fz_caught_message(ctx));
					fz_report_error(ctx);
				}
			}
		}
		ui_panel_end();
	}
	ui_dialog_end();
}

static int cert_file_filter(const char *fn)
{
	return !!strstr(fn, ".pfx");
}

static void cert_file_dialog(void)
{
	if (ui_open_file(cert_filename, "Select a certificate file to sign with:"))
	{
		if (cert_filename[0] != 0)
		{
			ui_input_init(&cert_password, "");
			ui.focus = &cert_password;
			ui.dialog = cert_password_dialog;
		}
		else
			ui.dialog = NULL;
	}
}

static void sig_sign_dialog(void)
{
	const char *label = pdf_field_label(ctx, pdf_annot_obj(ctx, sig_widget));

	ui_dialog_begin(ui.gridsize*16, (ui.gridsize+4)*3 + ui.lineheight*10);
	{
		ui_layout(T, X, NW, ui.padsize, ui.padsize);

		ui_label("%s", label);
		ui_spacer();

		ui_label("Would you like to sign this field?");

		ui_layout(B, X, NW, ui.padsize, ui.padsize);
		ui_panel_begin(0, ui.gridsize, 0, 0, 0);
		{
			ui_layout(R, NONE, S, 0, 0);
			if (ui_button("Cancel") || (!ui.focus && ui.key == KEY_ESCAPE))
				ui.dialog = NULL;
			ui_spacer();
			if (!(pdf_field_flags(ctx, pdf_annot_obj(ctx, sig_widget)) & PDF_FIELD_IS_READ_ONLY))
			{
				if (ui_button("Sign"))
				{
					fz_strlcpy(cert_filename, filename, sizeof cert_filename);
					ui_init_open_file(".", cert_file_filter);
					ui.dialog = cert_file_dialog;
				}
			}
		}
		ui_panel_end();
	}
	ui_dialog_end();
}

static void sig_verify_dialog(void)
{
	const char *label = pdf_field_label(ctx, pdf_annot_obj(ctx, sig_widget));

	ui_dialog_begin(ui.gridsize*16, (ui.gridsize+4)*3 + ui.lineheight*10);
	{
		ui_layout(T, X, NW, ui.padsize, ui.padsize);

		ui_label("%s", label);
		ui_spacer();

		if (sig_readonly)
		{
			ui_label("Signature field is read-only.");
			ui_spacer();
		}

		ui_label("Distinguished name: %s.", sig_distinguished_name);
		ui_spacer();

		if (sig_cert_error)
			ui_label("Certificate error: %s", pdf_signature_error_description(sig_cert_error));
		else
			ui_label("Certificate is trusted.");

		ui_spacer();

		if (sig_digest_error)
			ui_label("Digest error: %s", pdf_signature_error_description(sig_digest_error));
		else if (sig_valid_until == 0)
			ui_label("The fields signed by this signature are unchanged.");
		else if (sig_valid_until == 1)
			ui_label("This signature was invalidated in the last update by the signed fields being changed.");
		else if (sig_valid_until == 2)
			ui_label("This signature was invalidated in the penultimate update by the signed fields being changed.");
		else
			ui_label("This signature was invalidated %d updates ago by the signed fields being changed.", sig_valid_until);

		ui_layout(B, X, NW, ui.padsize, ui.padsize);
		ui_panel_begin(0, ui.gridsize, 0, 0, 0);
		{
			ui_layout(L, NONE, S, 0, 0);
			if (!sig_readonly)
			{
				if (ui_button("Clear"))
				{
					ui.dialog = NULL;
					do_clear_signature();
				}
			}
			ui_layout(R, NONE, S, 0, 0);
			if (ui_button("Close") || (!ui.focus && ui.key == KEY_ESCAPE))
				ui.dialog = NULL;
		}
		ui_panel_end();
	}
	ui_dialog_end();
}

static void show_sig_dialog(pdf_annot *widget)
{
	fz_try(ctx)
	{
		sig_widget = widget;

		if (pdf_signature_is_signed(ctx, pdf, pdf_annot_obj(ctx, widget)))
		{
			pdf_pkcs7_verifier *verifier;
			pdf_pkcs7_distinguished_name *dn;

			sig_readonly = pdf_widget_is_readonly(ctx, widget);

			sig_valid_until = pdf_validate_signature(ctx, widget);

			verifier = pkcs7_openssl_new_verifier(ctx);

			sig_cert_error = pdf_check_widget_certificate(ctx, verifier, widget);
			sig_digest_error = pdf_check_widget_digest(ctx, verifier, widget);

			fz_free(ctx, sig_distinguished_name);
			dn = pdf_signature_get_widget_signatory(ctx, verifier, widget);
			if (dn)
				sig_distinguished_name = pdf_signature_format_distinguished_name(ctx, dn);
			else
				sig_distinguished_name = fz_strdup(ctx, "Signature information missing.");
			pdf_signature_drop_distinguished_name(ctx, dn);

			pdf_drop_verifier(ctx, verifier);

			ui.dialog = sig_verify_dialog;
		}
		else
		{
			ui.dialog = sig_sign_dialog;
		}
	}
	fz_catch(ctx)
	{
		ui_show_warning_dialog("%s", fz_caught_message(ctx));
		fz_report_error(ctx);
	}
}

static pdf_annot *tx_widget;
static struct input tx_input;

static void tx_dialog(void)
{
	int ff = pdf_annot_field_flags(ctx, tx_widget);
	const char *label = pdf_annot_field_label(ctx, tx_widget);
	int tx_h = (ff & PDF_TX_FIELD_IS_MULTILINE) ? 10 : 1;
	int lbl_h = ui_break_lines((char*)label, NULL, 20, 394, NULL);
	int is;

	ui_dialog_begin(ui.gridsize*16, (ui.gridsize+4)*3 + ui.lineheight*(tx_h+lbl_h-2));
	{
		ui_layout(T, X, NW, ui.padsize, ui.padsize);
		ui_label("%s", label);
		tx_input.widget = tx_widget;
		is = ui_input(&tx_input, 200, tx_h);

		ui_layout(B, X, NW, ui.padsize, ui.padsize);
		ui_panel_begin(0, ui.gridsize, 0, 0, 0);
		{
			ui_layout(R, NONE, S, 0, 0);
			if (ui_button("Cancel") || (!ui.focus && ui.key == KEY_ESCAPE))
				ui.dialog = NULL;
			ui_spacer();
			if (ui_button("Okay") || is == UI_INPUT_ACCEPT)
			{
				if (pdf_set_text_field_value(ctx, tx_widget, tx_input.text))
				{
					trace_action("widget.setTextValue(%q);\n", tx_input.text);
					trace_field_value(tx_widget, tx_input.text);
					ui.dialog = NULL;
				}
			}
		}
		ui_panel_end();
	}
	ui_dialog_end();
}

void show_tx_dialog(pdf_annot *widget)
{
	ui_input_init(&tx_input, pdf_annot_field_value(ctx, widget));
	ui.focus = &tx_input;
	ui.dialog = tx_dialog;
	tx_widget = widget;
}

static pdf_annot *ch_widget;
static void ch_dialog(void)
{
	const char *label;
	const char *value;
	char **options;
	int n, choice;
	int label_h;

	label = pdf_field_label(ctx, pdf_annot_obj(ctx, ch_widget));
	label_h = ui_break_lines((char*)label, NULL, 20, 394, NULL);
	n = pdf_choice_widget_options(ctx, ch_widget, 0, NULL);
	options = fz_malloc_array(ctx, n, char *);
	pdf_choice_widget_options(ctx, ch_widget, 0, (const char **)options);
	value = pdf_field_value(ctx, pdf_annot_obj(ctx, ch_widget));

	ui_dialog_begin(ui.gridsize*16, (ui.gridsize+4)*3 + ui.lineheight*(label_h-1));
	{
		ui_layout(T, X, NW, ui.padsize, ui.padsize);

		ui_label("%s", label);
		choice = ui_select("Widget/Ch", value, (const char **)options, n);
		if (choice >= 0)
		{
			trace_action("widget.setChoiceValue(%q);\n", options[choice]);
			pdf_set_choice_field_value(ctx, ch_widget, options[choice]);
			trace_field_value(ch_widget, options[choice]);
		}

		ui_layout(B, X, NW, ui.padsize, ui.padsize);
		ui_panel_begin(0, ui.gridsize, 0, 0, 0);
		{
			ui_layout(R, NONE, S, 0, 0);
			if (ui_button("Cancel") || (!ui.focus && ui.key == KEY_ESCAPE))
				ui.dialog = NULL;
			ui_spacer();
			if (ui_button("Okay"))
			{
				ui.dialog = NULL;
			}
		}
		ui_panel_end();
	}
	ui_dialog_end();

	fz_free(ctx, options);
}

void do_widget_canvas(fz_irect canvas_area)
{
	pdf_annot *widget;
	fz_rect bounds;
	fz_irect area;
	int idx;

	if (!pdf)
		return;

	for (idx = 0, widget = pdf_first_widget(ctx, page); widget; ++idx, widget = pdf_next_widget(ctx, widget))
	{
		bounds = pdf_bound_widget(ctx, widget);
		bounds = fz_transform_rect(bounds, view_page_ctm);
		area = fz_irect_from_rect(bounds);

		if (ui_mouse_inside(canvas_area) && ui_mouse_inside(area))
		{
			if (!pdf_annot_hot(ctx, widget))
			{
				trace_action("page.getWidgets()[%d].eventEnter();\n", idx);
				pdf_annot_event_enter(ctx, widget);
			}
			pdf_set_annot_hot(ctx, widget, 1);

			ui.hot = widget;
			if (!ui.active && ui.down)
			{
				ui.active = widget;
				trace_action("page.getWidgets()[%d].eventDown();\n", idx);
				pdf_annot_event_down(ctx, widget);
				if (ui.selected_annot != widget)
				{
					if (ui.selected_annot && pdf_annot_type(ctx, ui.selected_annot) == PDF_ANNOT_WIDGET)
					{
						trace_action("widget.eventBlur();\n", idx);
						pdf_annot_event_blur(ctx, ui.selected_annot);
					}
					trace_action("widget = page.getWidgets()[%d];\n", idx);
					ui_select_annot(pdf_keep_annot(ctx, widget));
					trace_action("widget.eventFocus();\n");
					pdf_annot_event_focus(ctx, widget);
				}
			}
		}
		else
		{
			if (pdf_annot_hot(ctx, widget))
			{
				trace_action("page.getWidgets()[%d].eventExit();\n", idx);
				pdf_annot_event_exit(ctx, widget);
			}
			pdf_set_annot_hot(ctx, widget, 0);
		}

		/* Set is_hot and is_active to select current appearance */
		pdf_set_annot_active(ctx, widget, (ui.active == widget && ui.down));

		if (showform)
		{
			glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
			glEnable(GL_BLEND);
			glColor4f(0, 0, 1, 0.1f);
			glRectf(area.x0, area.y0, area.x1, area.y1);
			glDisable(GL_BLEND);
		}

		if (ui.active == widget || (!ui.active && ui.hot == widget))
		{
			glLineStipple(1, 0xAAAA);
			glEnable(GL_LINE_STIPPLE);
			glBlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ZERO);
			glEnable(GL_BLEND);
			glColor4f(1, 1, 1, 1);
			glBegin(GL_LINE_LOOP);
			glVertex2f(area.x0-0.5f, area.y0-0.5f);
			glVertex2f(area.x1+0.5f, area.y0-0.5f);
			glVertex2f(area.x1+0.5f, area.y1+0.5f);
			glVertex2f(area.x0-0.5f, area.y1+0.5f);
			glEnd();
			glDisable(GL_BLEND);
			glDisable(GL_LINE_STIPPLE);
		}

		if (ui.hot == widget && ui.active == widget && !ui.down)
		{
			trace_action("widget.eventUp();\n");
			pdf_annot_event_up(ctx, widget);

			if (pdf_widget_type(ctx, widget) == PDF_WIDGET_TYPE_SIGNATURE)
			{
				show_sig_dialog(widget);
			}
			else
			{
				if (pdf_annot_field_flags(ctx, widget) & PDF_FIELD_IS_READ_ONLY)
					continue;

				switch (pdf_widget_type(ctx, widget))
				{
				default:
					break;
				case PDF_WIDGET_TYPE_CHECKBOX:
				case PDF_WIDGET_TYPE_RADIOBUTTON:
					trace_action("widget.toggle();\n");
					pdf_toggle_widget(ctx, widget);
					break;
				case PDF_WIDGET_TYPE_TEXT:
					show_tx_dialog(widget);
					break;
				case PDF_WIDGET_TYPE_COMBOBOX:
				case PDF_WIDGET_TYPE_LISTBOX:
					ui.dialog = ch_dialog;
					ch_widget = widget;
					break;
				}
			}
		}
	}
}