[Solved] Synchronizing column widths between QTableViews

[Phlucious]

I have two tables displayed one above the other. The second table is a sorted/filtered/processed version of the first table, with exactly the same columns. I would like to have the columns of the second table line up exactly with the first table.

To accomplish this, I have trivially sub-classed QTableView and added a slot called MyTableView::updatedSectionWidth(int,int,int) that is linked to the standard implementation's QHeaderView::sectionResized(int,int,int) signal of the opposing table's horizontal header. The slot then synchronizes the receiving table's header view with the sending table's column width. When a user uses his mouse to resize the column in one table, the column in the other table resizes in sync, as expected.

I would like to resize the columns in both tables programmatically using QTableView::resizeColumnToContents. Unfortunately, that method does not appear to emit the sectionResized signal like I expected.

How can I accomplish the functionality I intend? Since the contents in the two tables might occupy a different amount of space, I cannot simply call resizeColumnToContents on both tables. I want them to match the width of the larger of the two tables. The following code does not appear to have the results I would expect:

ui->viewMain->resizeColumnToContents(columnid);
ui->viewSummary->resizeColumnToContents(columnid);
int mainsize = ui->viewMain->horizontalHeader()->sectionSize(columnid);
int summsize = ui->viewSummary->horizontalHeader()->sectionSize(columnid);
ui->viewMain->horizontalHeader()->resizeSection(columnid, qMax(mainsize, summsize));

ui->viewMain->resizeColumnToContents(columnid);
ui->viewSummary->resizeColumnToContents(columnid);
int mainsize = ui->viewMain->horizontalHeader()->sectionSize(columnid);
int summsize = ui->viewSummary->horizontalHeader()->sectionSize(columnid);
ui->viewMain->horizontalHeader()->resizeSection(columnid, qMax(mainsize, summsize));

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Added after 1:

Nevermind. The signal was getting emitted as expected, but resizing viewSummary overwrote the resizing of the first operation. The above code works when I temporarily block the signals as shown, and resize the viewSummary as well.

ui->viewMain->horizontalHeader()->blockSignals(true);
ui->viewSummary->horizontalHeader()->blockSignals(true);
 
ui->viewMain->resizeColumnToContents(columnid);
ui->viewSummary->resizeColumnToContents(columnid);
int mainsize = ui->viewMain->horizontalHeader()->sectionSize(columnid);
int summsize = ui->viewSummary->horizontalHeader()->sectionSize(columnid);
ui->viewMain->horizontalHeader()->resizeSection(columnid, qMax(mainsize, summsize));
ui->viewSummary->horizontalHeader()->resizeSection(cnum, qMax(mainsize, summsize));
 
ui->viewMain->horizontalHeader()->blockSignals(false);
ui->viewSummary->horizontalHeader()->blockSignals(false);

ui->viewMain->horizontalHeader()->blockSignals(true);
ui->viewSummary->horizontalHeader()->blockSignals(true);

ui->viewMain->resizeColumnToContents(columnid);
ui->viewSummary->resizeColumnToContents(columnid);
int mainsize = ui->viewMain->horizontalHeader()->sectionSize(columnid);
int summsize = ui->viewSummary->horizontalHeader()->sectionSize(columnid);
ui->viewMain->horizontalHeader()->resizeSection(columnid, qMax(mainsize, summsize));
ui->viewSummary->horizontalHeader()->resizeSection(cnum, qMax(mainsize, summsize));

ui->viewMain->horizontalHeader()->blockSignals(false);
ui->viewSummary->horizontalHeader()->blockSignals(false);

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This allows me to independently resize both tables to their contents, then resize them together using the larger of the two sizes.