chartsheet: add set_zoom_to_fit() method

Add a method to automatically zoom a chartsheet chart to fit the
screen.

Author: jmcnamara

lib/Excel/Writer/XLSX.pm

@@ -753,6 +753,7 @@ The following methods are available through a new worksheet:
     merge_range()
     merge_range_type()
     set_zoom()
+    set_zoom_to_fit()
     right_to_left()
     hide_zero()
     set_background()
@@ -2623,6 +2624,13 @@ The default zoom factor is 100. You cannot zoom to "Selection" because it is cal
 Note, C<set_zoom()> does not affect the scale of the printed page. For that you should use C<set_print_scale()>.
 
 
+=head2 set_zoom_to_fit()
+
+Set a chartsheet to zoom to fit the screen.
+
+This method is used to ensure that a chartsheet is zoomed automatically by Excel to fit the screen even when the window is resized.
+
+It only has an effect for chartsheets.
 
 
 =head2 right_to_left()

lib/Excel/Writer/XLSX/Chart.pm

@@ -9188,6 +9188,7 @@ The following Worksheet methods are also available through a non-embedded Chart
     set_first_sheet()
     protect()
     set_zoom()
+    set_zoom_to_fit()
     set_tab_color()
 
     set_landscape()

lib/Excel/Writer/XLSX/Worksheet.pm

@@ -77,6 +77,7 @@ sub new {
     $self->{_embedded_image_indexes} = $_[14];
     $self->{_embedded_images}        = $_[15];
 
+    $self->{_is_chartsheet} = 0;
     $self->{_ext_sheets}    = [];
     $self->{_fileclosed}    = 0;
     $self->{_excel_version} = 2007;
@@ -155,6 +156,7 @@ sub new {
 
     $self->{_zoom}              = 100;
     $self->{_zoom_scale_normal} = 1;
+    $self->{_zoom_to_fit}       = 0;
     $self->{_print_scale}       = 100;
     $self->{_right_to_left}     = 0;
     $self->{_show_zeros}        = 1;
@@ -2110,6 +2112,20 @@ sub set_zoom {
 }
 
 
+###############################################################################
+#
+# set_zoom_to_fit()
+#
+# Set the worksheet zoom  to selection/fit. Only works for chartsheets.
+#
+sub set_zoom_to_fit {
+
+    my $self = shift;
+
+    $self->{_zoom_to_fit} = 1;
+}
+
+
 ###############################################################################
 #
 # set_print_scale($scale)
@@ -7842,6 +7858,7 @@ sub _write_sheet_view {
     my $tab_selected     = $self->{_selected};
     my $view             = $self->{_page_view} || 0;
     my $zoom             = $self->{_zoom};
+    my $zoom_to_fit      = $self->{_zoom_to_fit};
     my $row_col_headers  = $self->{_hide_row_col_headers};
     my $top_left_cell    = $self->{_top_left_cell};
     my $workbook_view_id = 0;
@@ -7908,6 +7925,12 @@ sub _write_sheet_view {
 
     push @attributes, ( 'workbookViewId' => $workbook_view_id );
 
+    if ( $self->{_is_chartsheet} ) {
+        if ( $zoom_to_fit ) {
+            push @attributes, ( 'zoomToFit' => 1 );
+        }
+    }
+
     if ( @{ $self->{_panes} } || @{ $self->{_selections} } ) {
         $self->xml_start_tag( 'sheetView', @attributes );
         $self->_write_panes();

t/regression/chartsheet11.t

@@ -0,0 +1,90 @@
+###############################################################################
+#
+# Tests the output of Excel::Writer::XLSX against Excel generated files.
+#
+# Copyright 2000-2025, John McNamara, jmcnamara@cpan.org
+#
+# SPDX-License-Identifier: Artistic-1.0-Perl OR GPL-1.0-or-later
+#
+
+use lib 't/lib';
+use TestFunctions qw(_compare_xlsx_files _is_deep_diff);
+use strict;
+use warnings;
+
+use Test::More tests => 1;
+
+###############################################################################
+#
+# Tests setup.
+#
+my $filename     = 'chartsheet11.xlsx';
+my $dir          = 't/regression/';
+my $got_filename = $dir . "ewx_$filename";
+my $exp_filename = $dir . 'xlsx_files/' . $filename;
+
+my $ignore_members  = [];
+
+my $ignore_elements = { 'xl/workbook.xml' => ['<workbookView'] };
+
+
+###############################################################################
+#
+# Test the worksheet properties of an Excel::Writer::XLSX chartsheet file.
+#
+use Excel::Writer::XLSX;
+
+my $workbook  = Excel::Writer::XLSX->new( $got_filename );
+my $worksheet = $workbook->add_worksheet();
+my $chart     = $workbook->add_chart( type => 'bar' );
+
+# For testing, copy the randomly generated axis ids in the target xlsx file.
+$chart->{_chart}->{_axis_ids} = [ 63194240, 63195776 ];
+
+my $data = [
+    [ 1, 2, 3, 4,  5 ],
+    [ 2, 4, 6, 8,  10 ],
+    [ 3, 6, 9, 12, 15 ],
+
+];
+
+$worksheet->write( 'A1', $data );
+
+$chart->add_series( values => '=Sheet1!$A$1:$A$5' );
+$chart->add_series( values => '=Sheet1!$B$1:$B$5' );
+$chart->add_series( values => '=Sheet1!$C$1:$C$5' );
+
+# Chartsheet test.
+$chart->activate();
+
+$chart->set_zoom_to_fit();
+
+$workbook->close();
+
+
+###############################################################################
+#
+# Compare the generated and existing Excel files.
+#
+
+my ( $got, $expected, $caption ) = _compare_xlsx_files(
+
+    $got_filename,
+    $exp_filename,
+    $ignore_members,
+    $ignore_elements,
+);
+
+_is_deep_diff( $got, $expected, $caption );
+
+
+###############################################################################
+#
+# Cleanup.
+#
+unlink $got_filename;
+
+__END__
+
+
+