Column width

TreeGrid documentation

Every column can have set its width by Width otherwise its width is automatically calculated on start, but it can slow down the grid.
Every column's width can be also automatically calculated to fill all the main tag, set it by RelWidth.
Columns can be resized by a user, by mouse dragging.
Space row cells are independent on columns and have set their Width attributes.
Column width in pixels. It is outer width including all side buttons, cell border and padding.
If it is not set, it is automatically computed before the grid is first displayed according to the width of first few cells in the column.
If there any many columns, the automatic width calculation can slow down the rendering, so you should set Width for all or most of them!
If the cell content is wider than column width, it is overflowed in normal cells and wrapped in multiline cells (Type=Lines, Html, ...).
If set, the column width is automatically computed to fill all the remaining space in main tag.
The width is automatically recalculated whenever the width of the main tag or its content changes.
If there are more RelWidth columns in grid, their width is computed as ratio of their RelWidth values.
The RelWidth columns together fill the remaining vertical space in main tag, so the grid has always constant height of the main tag.
Using too many RelWidth columns can remarkably slow down grid usage!
You can set <fg ShowVScroll='1'/> to always show vertical scrollbar to speed up grid, especially in tree.
You can set minimal width by MinWidth.
It is ignored when set <Cfg NoHScroll or MaxHScroll or NoScroll /> attribute.
If the RelWidth column is resized by a user, it looses its capability and gets fixed width. Back to relative width can be forced by resizing it to zero width.
For successful printing set PrintWidth for the relative width column.
Changes RelWidth behavior. Bit array.

1. bit	&1	0 - Resizes the column to fill the main tag (the whole grid)
		1 - Resizes the column to fill its column section, the LeftWidth / MidWidth / RightWidth.
2. bit	&2	(new 12.0) If set with 1.bit, it shrinks the column until the column section hides its scrollbar.
3. bit	&4	(new 12.0) If set with 1.bit, it never hides column with MinWidth. If not set, it hides the column if it would be narrower than MinWidth.
4. bit	&8	(new 12.0) If set with 1.bit, it also resizes the column to fill the main tag (the whole grid) width.

Empty relative width column. Useful to automatically maximize column section (with RelWidthType='1') or the whole grid (with RelWidthType='0').
By default it is created by <Cfg ConstWidth/>.
It is completely inactive, with special empty CSS class.
Minimal width for width calculated on start (no Width set), for width calculated by RelWidth and for column resizing by a user.
If not set, minimal column width is cell border + padding.
If not set or set less than 20, resizing column by a user below the MinWidth sets the column to automatic width and calculates it according to its content.
Maximal width for width calculated on start (no Width set), for width calculated by RelWidth and for column resizing by a user.
A width of column when it is set as main column to show tree when grid is grouped.
You can specify this width to change column width when it becomes main column while grouping - to resize column to accommodate the tree.
When grid is ungrouped or it shows the tree in another column, the column width returns to previous setting.
Since 7.0, if set to 1, the width of the column will be automatically increased by the widths of columns hidden by grouping.
If and how the overlaying empty cells is done in the grid.
If set, permits using column attribute Overlay to overlay empty cells like in MS Excel.
Values 2 and higher can slow down the grid!
0 - No overlay is done.
1 - Simple fast overlay, default border remains between overlaid cells, all cells are overlaid to right. Row spanned cells cannot overlay next cells.
2 - Like 1 and border between overlaid cells is cleared.
3 - Like 2 and also overlays right aligned cell to left instead of right. And since 15.0 also centered cells to both sides.
3. bit &4 - since 15.0 permits overlay of row spanned cells (but without col span).
4. bit &8 - since 15.0 if two cells overlay the same next cell, the second overlay is restricted; if not set, the next cell value displays mangled value of the both overlay cells (e.g. A='long value, will not overlay B if 4. bit set ' B='' C='long value' D='will contain rest of A and C values overlaid if 4. bit not set').

Due internal implementation the overlaid (empty) cell can show overlapped (mangled) values from more than one cell even with Overlay=15 in these cases:
- If two cells overlay to the same (empty) cell and at least one from the two cells is row spanned.
- If right and left aligned cells overlay to the same (empty) cell and the values are shorter and do not overlay to the other overlay cell.
If the cell value can overlay next cells and if previous cell value can overlay this cell. Bit array. Used only if set <Cfg Overlay>
1. bit &1 - If the cell value can overlay next cells if it is wider than the cell width.
2. bit &2 - If previous cell will not overlay this cell if it has some value.
3. bit &4 - If set with 2.bit, the cell will not be overlaid either if it has empty value.
4. bit &8 - (new 14.0) It overlays also wrapped cells - the cell is extended horizontally if possible, rather than vertically. Requires <Cfg Overlay=2 or 3. For right aligned cells it is done always even without the 4. bit set.
Standard value for MS Excel like behavior is 3.
It never overlays: cells with side buttons, main column, cells between column sections, header and filter rows, cells spanned in both directions. In Chrome it does not overlay cells between column pages.
The cells overlaying next cells are ignored when calculating column width automatically.
If the cell images can overlay next cells in both directions.
0 - no
1 - only the floating images set by Img attribute
2 - also values of type Auto or EHtml with <img> tag and containing single <img> and white space
3 - also values of type Auto or EHtml with <img> tag and containing only <img> tags and white space
4 - also values of type Auto or EHtml with <img> tag and containing <img> tags and any other content
Use to speed up large grids with many cells on WebKit browsers (Chrome, Safari, Opera).
There is a bug in WebKit engine that causes the more tags with overflow:hidden is on page, the slower is every re-flow action on page.
You can define Overflow for all columns that are enough wide to show all theit content, so they don't need to overflow their cells content.
0 - Hidden, sets overflow:hidden to all column cells except empty. Standard, but slow.
1 - Visible, sets overflow:visible to all column cells. Fast, but the wider cell value overflows to next cell(s).
number - sets overflow:hidden to all cells if the column has Width < number or sets overflow:visible to all cells if the column has Width > number.
It does not affect Header and Filter rows, they always use overflow:hidden.
If column can be resized by a user by mouse dragging by column's right edge. The column resizing must be also permitted globally by <Cfg ColResizing='1'/>.
If set to 1, fixed column can also be resized automatically if there is no room for it, to preserve displaying "Too small extents" message.
All columns that have set <C CanResize='1'/> can be resized by a user.
If the cell checks its edges for mouse actions, bit array.
Default value is 2 for Header rows and 0 for other rows.
0 - no edge
1 - top and bottom edge for row resizing, event target is HeaderTop and HeaderBottom
2 - left and right edge for column resizing, event target is HeaderLeft and HeaderRight. Cannot be set for Space cell.
3 - both vertical and horizontal edges.
Set to columns containing wrap able cells, to shrink row height when the column is resized by a user and cells values occupy less height.
For 1 the rows are resized after column resizing finishes.
For 2 it resizes the rows during column resizing, it can be slow and should be used only for small grids.
This attribute also affect printing, see VarHeight.
Maximal count of rows to iterate when calculating column width.
Increasing the value can slow down the action.
Width of the Space cell in pixels. If not set, it has default value 100 and for Button and Label has -1. It is inner width without side buttons and border and cell padding.
It can be set to -1 to automatically calculate width according to cell content every time. If the cell value is changed, its width is updated.
It can be set to -2 to automatically calculate width according to cell content first time.
Minimal width of the cell for Width = -1 or -2. In pixels. Maximal width of the cell for Width = -1 or -2. In pixels. Minimal width of the tab cell if edited. In pixels. Usually used for renaming sheet.
Starts resizing column by mouse. This actions resizes also right side Pager.
By default is the action attached to OnDragHeaderLeft (header left edge), OnDragHeaderRight (header right edge) and OnDragPagerHeaderRight (right side pager header right edge).
Called when column is resized, by a user or due RelWidth or by API call SetWidth.
It can be called more times during resizing column by a user, for every change.
Called after column or right pager is resized by a user. Called only once.
(Since 9.2) row is the header row where the column edge was dragged.
(Since 9.2) chg is change of width in pixels.
Changes column with about dx pixels. Displays the change in grid.
The dx can be positive (enlarge) or negative (shrink). The resulted column width will be grid.Cols[col].Width + dx.
If the resulted width will be less than MinWidth, the column width is automatically calculated according to its content or it restores RelWidth if it was set.
Computes column width according to the first 100 (set by MaxCalcWidth) visible cells in this column, including all fixed cells and header.
In server paging if no rows are loaded yet it uses only fixed cells for calculation!
Since 13.2 if set rows it checks all these rows instead of the first 100. The rows array can be got by GetShownRows to check actually visible rows.
By default updates the column width in grid, if set noupdate = 1, it just sets the Width attribute.
This method is called on start for every column that has not set Width or RelWidth.
If the cell shows its content fully. Works only for already rendered cell.
Returns required change of the column width to show the whole cell content. Returns only 0 or positive value.