tableview.go

// Copyright 2011 The Walk Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// +build windows

package walk

import (
	"encoding/json"
	"fmt"
	"log"
	"math/big"
	"strconv"
	"strings"
	"syscall"
	"time"
	"unsafe"
)

import (
	"github.com/lxn/win"
)

var (
	defaultTVRowBGColor Color = Color(win.GetSysColor(win.COLOR_WINDOW))
	white                     = win.COLORREF(RGB(255, 255, 255))
)

const (
	tableViewCurrentIndexChangedTimerId = 1 + iota
	tableViewSelectedIndexesChangedTimerId
)

// TableView is a model based widget for record centric, tabular data.
//
// TableView is implemented as a virtual mode list view to support quite large
// amounts of data.
type TableView struct {
	WidgetBase
	columns                            *TableViewColumnList
	model                              TableModel
	providedModel                      interface{}
	itemChecker                        ItemChecker
	imageProvider                      ImageProvider
	hIml                               win.HIMAGELIST
	usingSysIml                        bool
	imageUintptr2Index                 map[uintptr]int32
	filePath2IconIndex                 map[string]int32
	rowsResetHandlerHandle             int
	rowChangedHandlerHandle            int
	sortChangedHandlerHandle           int
	prevIndex                          int
	currentIndex                       int
	currentIndexChangedPublisher       EventPublisher
	selectedIndexes                    *IndexList
	selectedIndexesChangedPublisher    EventPublisher
	itemActivatedPublisher             EventPublisher
	columnClickedPublisher             IntEventPublisher
	columnsOrderableChangedPublisher   EventPublisher
	columnsSizableChangedPublisher     EventPublisher
	lastColumnStretched                bool
	inEraseBkgnd                       bool
	persistent                         bool
	itemStateChangedEventDelay         int
	alternatingRowBGColor              Color
	hasDarkAltBGColor                  bool
	delayedCurrentIndexChangedCanceled bool
	sortedColumnIndex                  int
	sortOrder                          SortOrder
}

// NewTableView creates and returns a *TableView as child of the specified
// Container.
func NewTableView(parent Container) (*TableView, error) {
	return NewTableViewWithStyle(parent, win.LVS_SHOWSELALWAYS)
}

// NewTableViewWithStyle creates and returns a *TableView as child of the specified
// Container and with the provided additional style bits set.
func NewTableViewWithStyle(parent Container, style uint32) (*TableView, error) {
	tv := &TableView{
		alternatingRowBGColor: defaultTVRowBGColor,
		imageUintptr2Index:    make(map[uintptr]int32),
		filePath2IconIndex:    make(map[string]int32),
		selectedIndexes:       NewIndexList(nil),
	}

	tv.columns = newTableViewColumnList(tv)

	if err := InitWidget(
		tv,
		parent,
		"SysListView32",
		win.WS_TABSTOP|win.WS_VISIBLE|win.LVS_OWNERDATA|win.LVS_REPORT|style,
		win.WS_EX_CLIENTEDGE); err != nil {
		return nil, err
	}

	succeeded := false
	defer func() {
		if !succeeded {
			tv.Dispose()
		}
	}()

	tv.SetPersistent(true)

	exStyle := tv.SendMessage(win.LVM_GETEXTENDEDLISTVIEWSTYLE, 0, 0)
	exStyle |= win.LVS_EX_DOUBLEBUFFER | win.LVS_EX_FULLROWSELECT | win.LVS_EX_LABELTIP
	tv.SendMessage(win.LVM_SETEXTENDEDLISTVIEWSTYLE, 0, exStyle)

	if err := tv.setTheme("Explorer"); err != nil {
		return nil, err
	}

	tv.currentIndex = -1

	tv.MustRegisterProperty("ColumnsOrderable", NewBoolProperty(
		func() bool {
			return tv.ColumnsOrderable()
		},
		func(b bool) error {
			tv.SetColumnsOrderable(b)
			return nil
		},
		tv.columnsOrderableChangedPublisher.Event()))

	tv.MustRegisterProperty("ColumnsSizable", NewBoolProperty(
		func() bool {
			return tv.ColumnsSizable()
		},
		func(b bool) error {
			return tv.SetColumnsSizable(b)
		},
		tv.columnsSizableChangedPublisher.Event()))

	tv.MustRegisterProperty("HasCurrentItem", NewReadOnlyBoolProperty(
		func() bool {
			return tv.CurrentIndex() != -1
		},
		tv.CurrentIndexChanged()))

	succeeded = true

	return tv, nil
}

// Dispose releases the operating system resources, associated with the
// *TableView.
func (tv *TableView) Dispose() {
	tv.columns.unsetColumnsTV()

	tv.disposeImageListAndCaches()

	if tv.hWnd != 0 {
		if !win.KillTimer(tv.hWnd, tableViewCurrentIndexChangedTimerId) {
			lastError("KillTimer")
		}
		if !win.KillTimer(tv.hWnd, tableViewSelectedIndexesChangedTimerId) {
			lastError("KillTimer")
		}
	}

	tv.WidgetBase.Dispose()
}

// LayoutFlags returns a combination of LayoutFlags that specify how the
// *TableView wants to be treated by Layout implementations.
func (*TableView) LayoutFlags() LayoutFlags {
	return ShrinkableHorz | ShrinkableVert | GrowableHorz | GrowableVert | GreedyHorz | GreedyVert
}

// MinSizeHint returns the minimum outer Size, including decorations, that
// makes sense for the *TableView.
func (tv *TableView) MinSizeHint() Size {
	return Size{10, 10}
}

// SizeHint returns a sensible Size for a *TableView.
func (tv *TableView) SizeHint() Size {
	return Size{100, 100}
}

// ColumnsOrderable returns if the user can reorder columns by dragging and
// dropping column headers.
func (tv *TableView) ColumnsOrderable() bool {
	exStyle := tv.SendMessage(win.LVM_GETEXTENDEDLISTVIEWSTYLE, 0, 0)
	return exStyle&win.LVS_EX_HEADERDRAGDROP > 0
}

// SetColumnsOrderable sets if the user can reorder columns by dragging and
// dropping column headers.
func (tv *TableView) SetColumnsOrderable(enabled bool) {
	exStyle := tv.SendMessage(win.LVM_GETEXTENDEDLISTVIEWSTYLE, 0, 0)
	if enabled {
		exStyle |= win.LVS_EX_HEADERDRAGDROP
	} else {
		exStyle &^= win.LVS_EX_HEADERDRAGDROP
	}
	tv.SendMessage(win.LVM_SETEXTENDEDLISTVIEWSTYLE, 0, exStyle)

	tv.columnsOrderableChangedPublisher.Publish()
}

// ColumnsSizable returns if the user can change column widths by dragging
// dividers in the header.
func (tv *TableView) ColumnsSizable() bool {
	headerHWnd := win.HWND(tv.SendMessage(win.LVM_GETHEADER, 0, 0))

	style := win.GetWindowLong(headerHWnd, win.GWL_STYLE)

	return style&win.HDS_NOSIZING == 0
}

// SetColumnsSizable sets if the user can change column widths by dragging
// dividers in the header.
func (tv *TableView) SetColumnsSizable(b bool) error {
	headerHWnd := win.HWND(tv.SendMessage(win.LVM_GETHEADER, 0, 0))

	style := win.GetWindowLong(headerHWnd, win.GWL_STYLE)

	if b {
		style &^= win.HDS_NOSIZING
	} else {
		style |= win.HDS_NOSIZING
	}

	if 0 == win.SetWindowLong(headerHWnd, win.GWL_STYLE, style) {
		return lastError("SetWindowLong(GWL_STYLE)")
	}

	tv.columnsSizableChangedPublisher.Publish()

	return nil
}

// SortableByHeaderClick returns if the user can change sorting by clicking the header.
func (tv *TableView) SortableByHeaderClick() bool {
	return !tv.hasStyleBits(win.LVS_NOSORTHEADER)
}

// AlternatingRowBGColor returns the alternating row background color.
func (tv *TableView) AlternatingRowBGColor() Color {
	return tv.alternatingRowBGColor
}

// SetAlternatingRowBGColor sets the alternating row background color.
func (tv *TableView) SetAlternatingRowBGColor(c Color) {
	tv.alternatingRowBGColor = c

	tv.hasDarkAltBGColor = int(c.R())+int(c.G())+int(c.B()) < 128*3

	tv.Invalidate()
}

// Columns returns the list of columns.
func (tv *TableView) Columns() *TableViewColumnList {
	return tv.columns
}

// VisibleColumnsInDisplayOrder returns a slice of visible columns in display
// order.
func (tv *TableView) VisibleColumnsInDisplayOrder() []*TableViewColumn {
	visibleCols := tv.visibleColumns()
	indices := make([]int32, len(visibleCols))

	if win.FALSE == tv.SendMessage(win.LVM_GETCOLUMNORDERARRAY, uintptr(len(indices)), uintptr(unsafe.Pointer(&indices[0]))) {
		newError("LVM_GETCOLUMNORDERARRAY")
		return nil
	}

	orderedCols := make([]*TableViewColumn, len(visibleCols))

	for i, j := range indices {
		orderedCols[i] = visibleCols[j]
	}

	return orderedCols
}

// RowsPerPage returns the number of fully visible rows.
func (tv *TableView) RowsPerPage() int {
	return int(tv.SendMessage(win.LVM_GETCOUNTPERPAGE, 0, 0))
}

// UpdateItem ensures the item at index will be redrawn.
//
// If the model supports sorting, it will be resorted.
func (tv *TableView) UpdateItem(index int) error {
	if s, ok := tv.model.(Sorter); ok {
		if err := s.Sort(s.SortedColumn(), s.SortOrder()); err != nil {
			return err
		}

		return tv.Invalidate()
	} else {
		if win.FALSE == tv.SendMessage(win.LVM_UPDATE, uintptr(index), 0) {
			return newError("LVM_UPDATE")
		}
	}

	return nil
}

func (tv *TableView) attachModel() {
	tv.rowsResetHandlerHandle = tv.model.RowsReset().Attach(func() {
		tv.setItemCount()

		tv.SetCurrentIndex(-1)
	})

	tv.rowChangedHandlerHandle = tv.model.RowChanged().Attach(func(row int) {
		tv.UpdateItem(row)
	})

	if sorter, ok := tv.model.(Sorter); ok {
		tv.sortChangedHandlerHandle = sorter.SortChanged().Attach(func() {
			col := sorter.SortedColumn()
			tv.setSelectedColumnIndex(col)
			tv.setSortIcon(col, sorter.SortOrder())
			tv.Invalidate()
		})
	}
}

func (tv *TableView) detachModel() {
	tv.model.RowsReset().Detach(tv.rowsResetHandlerHandle)
	tv.model.RowChanged().Detach(tv.rowChangedHandlerHandle)
	if sorter, ok := tv.model.(Sorter); ok {
		sorter.SortChanged().Detach(tv.sortChangedHandlerHandle)
	}
}

// Model returns the model of the TableView.
func (tv *TableView) Model() interface{} {
	return tv.providedModel
}

// SetModel sets the model of the TableView.
//
// It is required that mdl either implements walk.TableModel,
// walk.ReflectTableModel or be a slice of pointers to struct or a
// []map[string]interface{}. A walk.TableModel implementation must also
// implement walk.Sorter to support sorting, all other options get sorting for
// free. To support item check boxes and icons, mdl must implement
// walk.ItemChecker and walk.ImageProvider, respectively. On-demand model
// population for a walk.ReflectTableModel or slice requires mdl to implement
// walk.Populator.
func (tv *TableView) SetModel(mdl interface{}) error {
	model, ok := mdl.(TableModel)
	if !ok && mdl != nil {
		var err error
		if model, err = newReflectTableModel(mdl); err != nil {
			if model, err = newMapTableModel(mdl); err != nil {
				return err
			}
		}
	}
	tv.providedModel = mdl

	tv.SetSuspended(true)
	defer tv.SetSuspended(false)

	if tv.model != nil {
		tv.detachModel()

		tv.disposeImageListAndCaches()
	}

	tv.model = model

	tv.itemChecker, _ = model.(ItemChecker)
	tv.imageProvider, _ = model.(ImageProvider)

	if model != nil {
		tv.attachModel()

		if dms, ok := model.(dataMembersSetter); ok {
			// FIXME: This depends on columns to be initialized before
			// calling this method.
			dataMembers := make([]string, len(tv.columns.items))

			for i, col := range tv.columns.items {
				dataMembers[i] = col.DataMemberEffective()
			}

			dms.setDataMembers(dataMembers)
		}

		if sorter, ok := tv.model.(Sorter); ok {
			sorter.Sort(tv.sortedColumnIndex, tv.sortOrder)
		}
	}

	tv.SetCurrentIndex(-1)

	return tv.setItemCount()
}

// TableModel returns the TableModel of the TableView.
func (tv *TableView) TableModel() TableModel {
	return tv.model
}

func (tv *TableView) setItemCount() error {
	var count int

	if tv.model != nil {
		count = tv.model.RowCount()
	}

	if 0 == tv.SendMessage(win.LVM_SETITEMCOUNT, uintptr(count), win.LVSICF_NOSCROLL) {
		return newError("SendMessage(LVM_SETITEMCOUNT)")
	}

	return nil
}

// CheckBoxes returns if the *TableView has check boxes.
func (tv *TableView) CheckBoxes() bool {
	return tv.SendMessage(win.LVM_GETEXTENDEDLISTVIEWSTYLE, 0, 0)&win.LVS_EX_CHECKBOXES > 0
}

// SetCheckBoxes sets if the *TableView has check boxes.
func (tv *TableView) SetCheckBoxes(value bool) {
	exStyle := tv.SendMessage(win.LVM_GETEXTENDEDLISTVIEWSTYLE, 0, 0)
	oldStyle := exStyle
	if value {
		exStyle |= win.LVS_EX_CHECKBOXES
	} else {
		exStyle &^= win.LVS_EX_CHECKBOXES
	}
	if exStyle != oldStyle {
		tv.SendMessage(win.LVM_SETEXTENDEDLISTVIEWSTYLE, 0, exStyle)
	}

	mask := tv.SendMessage(win.LVM_GETCALLBACKMASK, 0, 0)

	if value {
		mask |= win.LVIS_STATEIMAGEMASK
	} else {
		mask &^= win.LVIS_STATEIMAGEMASK
	}

	if win.FALSE == tv.SendMessage(win.LVM_SETCALLBACKMASK, mask, 0) {
		newError("SendMessage(LVM_SETCALLBACKMASK)")
	}
}

func (tv *TableView) fromLVColIdx(index int32) int {
	var idx int32

	for i, tvc := range tv.columns.items {
		if tvc.visible {
			if idx == index {
				return i
			}

			idx++
		}
	}

	return -1
}

func (tv *TableView) toLVColIdx(index int) int32 {
	var idx int32

	for i, tvc := range tv.columns.items {
		if tvc.visible {
			if i == index {
				return idx
			}

			idx++
		}
	}

	return -1
}

func (tv *TableView) visibleColumnCount() int {
	var count int

	for _, tvc := range tv.columns.items {
		if tvc.visible {
			count++
		}
	}

	return count
}

func (tv *TableView) visibleColumns() []*TableViewColumn {
	var cols []*TableViewColumn

	for _, tvc := range tv.columns.items {
		if tvc.visible {
			cols = append(cols, tvc)
		}
	}

	return cols
}

/*func (tv *TableView) selectedColumnIndex() int {
	return tv.fromLVColIdx(tv.SendMessage(LVM_GETSELECTEDCOLUMN, 0, 0))
}*/

func (tv *TableView) setSelectedColumnIndex(index int) {
	tv.SendMessage(win.LVM_SETSELECTEDCOLUMN, uintptr(tv.toLVColIdx(index)), 0)
}

func (tv *TableView) setSortIcon(index int, order SortOrder) error {
	headerHwnd := win.HWND(tv.SendMessage(win.LVM_GETHEADER, 0, 0))

	idx := int(tv.toLVColIdx(index))

	for i := range tv.visibleColumns() {
		item := win.HDITEM{
			Mask: win.HDI_FORMAT,
		}

		iPtr := uintptr(i)
		itemPtr := uintptr(unsafe.Pointer(&item))

		if win.SendMessage(headerHwnd, win.HDM_GETITEM, iPtr, itemPtr) == 0 {
			return newError("SendMessage(HDM_GETITEM)")
		}

		if i == idx {
			switch order {
			case SortAscending:
				item.Fmt &^= win.HDF_SORTDOWN
				item.Fmt |= win.HDF_SORTUP

			case SortDescending:
				item.Fmt &^= win.HDF_SORTUP
				item.Fmt |= win.HDF_SORTDOWN
			}
		} else {
			item.Fmt &^= win.HDF_SORTDOWN | win.HDF_SORTUP
		}

		if win.SendMessage(headerHwnd, win.HDM_SETITEM, iPtr, itemPtr) == 0 {
			return newError("SendMessage(HDM_SETITEM)")
		}
	}

	return nil
}

// ColumnClicked returns the event that is published after a column header was
// clicked.
func (tv *TableView) ColumnClicked() *IntEvent {
	return tv.columnClickedPublisher.Event()
}

// ItemActivated returns the event that is published after an item was
// activated.
//
// An item is activated when it is double clicked or the enter key is pressed
// when the item is selected.
func (tv *TableView) ItemActivated() *Event {
	return tv.itemActivatedPublisher.Event()
}

// CurrentIndex returns the index of the current item, or -1 if there is no
// current item.
func (tv *TableView) CurrentIndex() int {
	return tv.currentIndex
}

// SetCurrentIndex sets the index of the current item.
//
// Call this with a value of -1 to have no current item.
func (tv *TableView) SetCurrentIndex(value int) error {
	var lvi win.LVITEM

	lvi.StateMask = win.LVIS_FOCUSED | win.LVIS_SELECTED
	if value > -1 {
		lvi.State = win.LVIS_FOCUSED | win.LVIS_SELECTED
	}

	if win.FALSE == tv.SendMessage(win.LVM_SETITEMSTATE, uintptr(value), uintptr(unsafe.Pointer(&lvi))) {
		return newError("SendMessage(LVM_SETITEMSTATE)")
	}

	if value != -1 {
		if win.FALSE == tv.SendMessage(win.LVM_ENSUREVISIBLE, uintptr(value), uintptr(0)) {
			return newError("SendMessage(LVM_ENSUREVISIBLE)")
		}
		// Windows bug? Sometimes a second LVM_ENSUREVISIBLE is required.
		if win.FALSE == tv.SendMessage(win.LVM_ENSUREVISIBLE, uintptr(value), uintptr(0)) {
			return newError("SendMessage(LVM_ENSUREVISIBLE)")
		}
	}

	tv.currentIndex = value

	if value == -1 {
		tv.currentIndexChangedPublisher.Publish()
	}

	return nil
}

// CurrentIndexChanged is the event that is published after CurrentIndex has
// changed.
func (tv *TableView) CurrentIndexChanged() *Event {
	return tv.currentIndexChangedPublisher.Event()
}

// SingleItemSelection returns if only a single item can be selected at once.
//
// By default multiple items can be selected at once.
func (tv *TableView) SingleItemSelection() bool {
	style := uint(win.GetWindowLong(tv.hWnd, win.GWL_STYLE))
	if style == 0 {
		lastError("GetWindowLong")
		return false
	}

	return style&win.LVS_SINGLESEL > 0
}

// SetSingleItemSelection sets if only a single item can be selected at once.
func (tv *TableView) SetSingleItemSelection(value bool) error {
	return tv.ensureStyleBits(win.LVS_SINGLESEL, value)
}

// SelectedIndexes returns a list of the currently selected item indexes.
func (tv *TableView) SelectedIndexes() *IndexList {
	return tv.selectedIndexes
}

// ItemStateChangedEventDelay returns the delay in milliseconds, between the
// moment the state of an item in the *TableView changes and the moment the
// associated event is published.
//
// By default there is no delay.
func (tv *TableView) ItemStateChangedEventDelay() int {
	return tv.itemStateChangedEventDelay
}

// SetItemStateChangedEventDelay sets the delay in milliseconds, between the
// moment the state of an item in the *TableView changes and the moment the
// associated event is published.
//
// An example where this may be useful is a master-details scenario. If the
// master TableView is configured to delay the event, you can avoid pointless
// updates of the details TableView, if the user uses arrow keys to rapidly
// navigate the master view.
func (tv *TableView) SetItemStateChangedEventDelay(delay int) {
	tv.itemStateChangedEventDelay = delay
}

func (tv *TableView) updateSelectedIndexes() {
	count := int(tv.SendMessage(win.LVM_GETSELECTEDCOUNT, 0, 0))
	indexes := make([]int, count)

	j := -1
	for i := 0; i < count; i++ {
		j = int(tv.SendMessage(win.LVM_GETNEXTITEM, uintptr(j), win.LVNI_SELECTED))
		indexes[i] = j
	}

	changed := len(indexes) != len(tv.selectedIndexes.items)
	if !changed {
		for i := 0; i < len(indexes); i++ {
			if indexes[i] != tv.selectedIndexes.items[i] {
				changed = true
				break
			}
		}
	}

	if changed {
		tv.selectedIndexes.items = indexes
		if tv.itemStateChangedEventDelay > 0 {
			if 0 == win.SetTimer(
				tv.hWnd,
				tableViewSelectedIndexesChangedTimerId,
				uint32(tv.itemStateChangedEventDelay),
				0) {

				lastError("SetTimer")
			}
		} else {
			tv.selectedIndexesChangedPublisher.Publish()
		}
	}
}

// SelectedIndexesChanged returns the event that is published when the list of
// selected item indexes changed.
func (tv *TableView) SelectedIndexesChanged() *Event {
	return tv.selectedIndexesChangedPublisher.Event()
}

// LastColumnStretched returns if the last column should take up all remaining
// horizontal space of the *TableView.
func (tv *TableView) LastColumnStretched() bool {
	return tv.lastColumnStretched
}

// SetLastColumnStretched sets if the last column should take up all remaining
// horizontal space of the *TableView.
//
// The effect of setting this is persistent.
func (tv *TableView) SetLastColumnStretched(value bool) error {
	if value {
		if err := tv.StretchLastColumn(); err != nil {
			return err
		}
	}

	tv.lastColumnStretched = value

	return nil
}

// StretchLastColumn makes the last column take up all remaining horizontal
// space of the *TableView.
//
// The effect of this is not persistent.
func (tv *TableView) StretchLastColumn() error {
	colCount := tv.visibleColumnCount()
	if colCount == 0 {
		return nil
	}

	if 0 == tv.SendMessage(win.LVM_SETCOLUMNWIDTH, uintptr(colCount-1), win.LVSCW_AUTOSIZE_USEHEADER) {
		return newError("LVM_SETCOLUMNWIDTH failed")
	}

	return nil
}

// Persistent returns if the *TableView should persist its UI state, like column
// widths. See *App.Settings for details.
func (tv *TableView) Persistent() bool {
	return tv.persistent
}

// SetPersistent sets if the *TableView should persist its UI state, like column
// widths. See *App.Settings for details.
func (tv *TableView) SetPersistent(value bool) {
	tv.persistent = value
}

type tableViewState struct {
	SortColumnName     string
	SortOrder          SortOrder
	ColumnDisplayOrder []string // Also indicates visibility
	Columns            []tableViewColumnState
}

type tableViewColumnState struct {
	Name  string
	Title string
	Width int
}

// SaveState writes the UI state of the *TableView to the settings.
func (tv *TableView) SaveState() error {
	var tvs tableViewState

	tvs.SortColumnName = tv.columns.items[tv.sortedColumnIndex].name
	tvs.SortOrder = tv.sortOrder

	tvs.Columns = make([]tableViewColumnState, tv.columns.Len())

	for i, tvc := range tv.columns.items {
		tvcs := &tvs.Columns[i]

		tvcs.Name = tvc.name
		tvcs.Title = tvc.titleOverride
		tvcs.Width = tvc.Width()
	}

	visibleCols := tv.visibleColumns()
	indices := make([]int32, len(visibleCols))
	var lParam uintptr
	if len(visibleCols) > 0 {
		lParam = uintptr(unsafe.Pointer(&indices[0]))
	}
	if 0 == tv.SendMessage(win.LVM_GETCOLUMNORDERARRAY, uintptr(len(visibleCols)), lParam) {
		return newError("LVM_GETCOLUMNORDERARRAY")
	}

	tvs.ColumnDisplayOrder = make([]string, len(visibleCols))
	for i, j := range indices {
		tvs.ColumnDisplayOrder[i] = visibleCols[j].name
	}

	state, err := json.Marshal(tvs)
	if err != nil {
		return err
	}

	return tv.putState(string(state))
}

// RestoreState restores the UI state of the *TableView from the settings.
func (tv *TableView) RestoreState() error {
	state, err := tv.getState()
	if err != nil {
		return err
	}
	if state == "" {
		return nil
	}

	tv.SetSuspended(true)
	defer tv.SetSuspended(false)

	var tvs tableViewState

	if err := json.Unmarshal(([]byte)(state), &tvs); err != nil {
		return tv.restoreStateOldStyle(state)
	}

	name2tvc := make(map[string]*TableViewColumn)

	for _, tvc := range tv.columns.items {
		name2tvc[tvc.name] = tvc
	}

	name2tvcs := make(map[string]*tableViewColumnState)

	for i, tvcs := range tvs.Columns {
		name2tvcs[tvcs.Name] = &tvs.Columns[i]

		if tvc := name2tvc[tvcs.Name]; tvc != nil {
			if err := tvc.SetTitleOverride(tvcs.Title); err != nil {
				return err
			}
			if err := tvc.SetWidth(tvcs.Width); err != nil {
				return err
			}
			var visible bool
			for _, name := range tvs.ColumnDisplayOrder {
				if name == tvc.name {
					visible = true
					break
				}
			}
			if err := tvc.SetVisible(visible); err != nil {
				return err
			}
		}
	}

	visibleCount := tv.visibleColumnCount()

	indices := make([]int32, visibleCount)

	knownNames := make(map[string]struct{})

	displayOrder := make([]string, 0, visibleCount)
	for _, name := range tvs.ColumnDisplayOrder {
		knownNames[name] = struct{}{}
		if _, ok := name2tvc[name]; ok {
			displayOrder = append(displayOrder, name)
		}
	}
	for _, tvc := range tv.visibleColumns() {
		if _, ok := knownNames[tvc.name]; !ok {
			displayOrder = append(displayOrder, tvc.name)
		}
	}

	for i, tvc := range tv.visibleColumns() {
		for j, name := range displayOrder {
			if tvc.name == name {
				indices[j] = int32(i)
				break
			}
		}
	}

	wParam := uintptr(len(indices))
	var lParam uintptr
	if len(indices) > 0 {
		lParam = uintptr(unsafe.Pointer(&indices[0]))
	}
	if 0 == tv.SendMessage(win.LVM_SETCOLUMNORDERARRAY, wParam, lParam) {
		return newError("LVM_SETCOLUMNORDERARRAY")
	}

	for i, c := range tvs.Columns {
		if c.Name == tvs.SortColumnName {
			tv.sortedColumnIndex = i
			tv.sortOrder = tvs.SortOrder
			break
		}
	}

	if sorter, ok := tv.model.(Sorter); ok {
		if !sorter.ColumnSortable(tv.sortedColumnIndex) {
			for i := range tvs.Columns {
				if sorter.ColumnSortable(i) {
					tv.sortedColumnIndex = i
				}
			}
		}

		sorter.Sort(tv.sortedColumnIndex, tvs.SortOrder)
	}

	//if sorter, ok := tv.model.(Sorter); ok {
	//	index := -1
	//	order := SortAscending

	//	for i, c := range tvs.Columns {
	//		if tv.columns.items[i].visible && sorter.ColumnSortable(i) {
	//			if c.Name == tvs.SortColumnName {
	//				index = i
	//				order = tvs.SortOrder
	//				break
	//			} else if index == -1 {
	//				index = i
	//			}
	//		}
	//	}

	//	if index > -1 {
	//		sorter.Sort(index, order)
	//	}
	//}

	return nil
}

//// SaveState writes the UI state of the *TableView to the settings.
//func (tv *TableView) SaveState() error {
//	buf := new(bytes.Buffer)

//	count := tv.columns.Len()
//	if count > 0 {
//		for i := 0; i < count; i++ {
//			if i > 0 {
//				buf.WriteString(" ")
//			}

//			width := tv.Columns().At(i).Width()
//			if width == 0 {
//				width = 100
//			}

//			buf.WriteString(strconv.Itoa(int(width)))
//		}

//		buf.WriteString(";")

//		visibleCount := tv.visibleColumnCount()

//		indices := make([]int32, visibleCount)
//		lParam := uintptr(unsafe.Pointer(&indices[0]))

//		if 0 == tv.SendMessage(win.LVM_GETCOLUMNORDERARRAY, uintptr(visibleCount), lParam) {
//			return newError("LVM_GETCOLUMNORDERARRAY")
//		}

//		for i, idx := range indices {
//			if i > 0 {
//				buf.WriteString(" ")
//			}

//			buf.WriteString(strconv.Itoa(int(idx)))
//		}

//		buf.WriteString(";")

//		for i, tvc := range tv.columns.items {
//			if i > 0 {
//				buf.WriteString("|")
//			}

//			buf.WriteString(tvc.TitleOverride())
//		}

//		buf.WriteString(";")

//		for i, tvc := range tv.columns.items {
//			if i > 0 {
//				buf.WriteString(" ")
//			}

//			if tvc.Visible() {
//				buf.WriteString("1")
//			} else {
//				buf.WriteString("0")
//			}
//		}

//		buf.WriteString(";")

//		if sorter, ok := tv.model.(Sorter); ok {
//			buf.WriteString(strconv.Itoa(sorter.SortedColumn()))
//			buf.WriteString(" ")
//			buf.WriteString(strconv.Itoa(int(sorter.SortOrder())))
//		} else {
//			buf.WriteString("- -")
//		}
//	}

//	return tv.putState(buf.String())
//}

func (tv *TableView) restoreStateOldStyle(state string) error {
	parts := strings.Split(state, ";")

	widthStrs := strings.Split(parts[0], " ")

	// FIXME: Solve this in a better way.
	if len(widthStrs) > tv.columns.Len() {
		log.Print("*TableView.RestoreState: failed due to unexpected column count (FIXME!)")
		return nil
	}

	// Do visibility stuff first.
	if len(parts) > 3 {
		visible := strings.Split(parts[3], " ")

		for i, v := range visible {
			if err := tv.columns.At(i).SetVisible(v == "1"); err != nil {
				return err
			}
		}
	}

	for i, str := range widthStrs {
		width, err := strconv.Atoi(str)
		if err != nil {
			return err
		}

		if err := tv.Columns().At(i).SetWidth(width); err != nil {
			return err
		}
	}

	if len(parts) > 1 {
		indexStrs := strings.Split(parts[1], " ")

		indices := make([]int32, len(indexStrs))

		var failed bool
		for i, s := range indexStrs {
			idx, err := strconv.Atoi(s)
			if err != nil {
				failed = true
				break
			}
			indices[i] = int32(idx)
		}

		if !failed {
			wParam := uintptr(len(indices))
			lParam := uintptr(unsafe.Pointer(&indices[0]))
			if 0 == tv.SendMessage(win.LVM_SETCOLUMNORDERARRAY, wParam, lParam) {
				return newError("LVM_SETCOLUMNORDERARRAY")
			}
		}
	}

	if len(parts) > 2 {
		titleOverrides := strings.Split(parts[2], "|")

		for i, to := range titleOverrides {
			if err := tv.columns.At(i).SetTitleOverride(to); err != nil {
				return err
			}
		}
	}

	if sorter, ok := tv.model.(Sorter); ok && len(parts) > 4 {
		sortParts := strings.Split(parts[4], " ")
		if colStr := sortParts[0]; colStr != "-" {
			col, err := strconv.Atoi(colStr)
			if err != nil {
				return err
			}
			if sorter.ColumnSortable(col) {
				ord, err := strconv.Atoi(sortParts[1])
				if err != nil {
					return err
				}
				if err := sorter.Sort(col, SortOrder(ord)); err != nil {
					return err
				}
			}
		}
	}

	return nil
}

func (tv *TableView) toggleItemChecked(index int) error {
	checked := tv.itemChecker.Checked(index)

	if err := tv.itemChecker.SetChecked(index, !checked); err != nil {
		return wrapError(err)
	}

	if win.FALSE == tv.SendMessage(win.LVM_UPDATE, uintptr(index), 0) {
		return newError("SendMessage(LVM_UPDATE)")
	}

	return nil
}

func (tv *TableView) applyImageListForImage(image interface{}) {
	tv.hIml, tv.usingSysIml, _ = imageListForImage(image)

	tv.SendMessage(win.LVM_SETIMAGELIST, win.LVSIL_SMALL, uintptr(tv.hIml))

	tv.imageUintptr2Index = make(map[uintptr]int32)
	tv.filePath2IconIndex = make(map[string]int32)
}

func (tv *TableView) disposeImageListAndCaches() {
	if tv.hIml != 0 && !tv.usingSysIml {
		tv.SendMessage(win.LVM_SETIMAGELIST, win.LVSIL_SMALL, 0)

		win.ImageList_Destroy(tv.hIml)
	}
	tv.hIml = 0

	tv.imageUintptr2Index = nil
	tv.filePath2IconIndex = nil
}

func (tv *TableView) WndProc(hwnd win.HWND, msg uint32, wParam, lParam uintptr) uintptr {
	switch msg {
	case win.WM_ERASEBKGND:
		if tv.lastColumnStretched && !tv.inEraseBkgnd {
			tv.inEraseBkgnd = true
			defer func() {
				tv.inEraseBkgnd = false
			}()
			tv.StretchLastColumn()
		}
		return 1

	case win.WM_GETDLGCODE:
		if wParam == win.VK_RETURN {
			return win.DLGC_WANTALLKEYS
		}

	case win.WM_LBUTTONDOWN, win.WM_RBUTTONDOWN, win.WM_LBUTTONDBLCLK, win.WM_RBUTTONDBLCLK:
		var hti win.LVHITTESTINFO
		hti.Pt = win.POINT{win.GET_X_LPARAM(lParam), win.GET_Y_LPARAM(lParam)}
		tv.SendMessage(win.LVM_HITTEST, 0, uintptr(unsafe.Pointer(&hti)))

		if hti.Flags == win.LVHT_NOWHERE && tv.SingleItemSelection() {
			// We keep the current item, if in single item selection mode.
			tv.SetFocus()
			return 0
		}

		switch msg {
		case win.WM_LBUTTONDOWN, win.WM_RBUTTONDOWN:
			if hti.Flags == win.LVHT_ONITEMSTATEICON &&
				tv.itemChecker != nil &&
				tv.CheckBoxes() {

				tv.toggleItemChecked(int(hti.IItem))
			}

		case win.WM_LBUTTONDBLCLK, win.WM_RBUTTONDBLCLK:
			if tv.currentIndex != tv.prevIndex && tv.itemStateChangedEventDelay > 0 {
				tv.prevIndex = tv.currentIndex
				tv.currentIndexChangedPublisher.Publish()
			}
		}

	case win.WM_KEYDOWN:
		if wParam == win.VK_SPACE &&
			tv.currentIndex > -1 &&
			tv.itemChecker != nil &&
			tv.CheckBoxes() {

			tv.toggleItemChecked(tv.currentIndex)
		}

	case win.WM_NOTIFY:
		switch ((*win.NMHDR)(unsafe.Pointer(lParam))).Code {
		case win.LVN_GETDISPINFO:
			di := (*win.NMLVDISPINFO)(unsafe.Pointer(lParam))

			row := int(di.Item.IItem)
			col := tv.fromLVColIdx(di.Item.ISubItem)

			if di.Item.Mask&win.LVIF_TEXT > 0 {
				var text string
				switch val := tv.model.Value(row, col).(type) {
				case string:
					text = val

				case float32:
					prec := tv.columns.items[col].precision
					if prec == 0 {
						prec = 2
					}
					text = FormatFloatGrouped(float64(val), prec)

				case float64:
					prec := tv.columns.items[col].precision
					if prec == 0 {
						prec = 2
					}
					text = FormatFloatGrouped(val, prec)

				case time.Time:
					if val.Year() > 1601 {
						text = val.Format(tv.columns.items[col].format)
					}

				case *big.Rat:
					prec := tv.columns.items[col].precision
					if prec == 0 {
						prec = 2
					}
					text = formatBigRatGrouped(val, prec)

				default:
					text = fmt.Sprintf(tv.columns.items[col].format, val)
				}

				utf16 := syscall.StringToUTF16(text)
				buf := (*[264]uint16)(unsafe.Pointer(di.Item.PszText))
				max := mini(len(utf16), int(di.Item.CchTextMax))
				copy((*buf)[:], utf16[:max])
				(*buf)[max-1] = 0
			}

			if tv.imageProvider != nil && di.Item.Mask&win.LVIF_IMAGE > 0 {
				if image := tv.imageProvider.Image(row); image != nil {
					if tv.hIml == 0 {
						tv.applyImageListForImage(image)
					}

					di.Item.IImage = imageIndexMaybeAdd(
						image,
						tv.hIml,
						tv.usingSysIml,
						tv.imageUintptr2Index,
						tv.filePath2IconIndex)
				}
			}

			if di.Item.StateMask&win.LVIS_STATEIMAGEMASK > 0 &&
				tv.itemChecker != nil {
				checked := tv.itemChecker.Checked(row)

				if checked {
					di.Item.State = 0x2000
				} else {
					di.Item.State = 0x1000
				}
			}

		case win.NM_CUSTOMDRAW:
			if tv.alternatingRowBGColor != defaultTVRowBGColor {
				nmlvcd := (*win.NMLVCUSTOMDRAW)(unsafe.Pointer(lParam))

				switch nmlvcd.Nmcd.DwDrawStage {
				case win.CDDS_PREPAINT:
					return win.CDRF_NOTIFYITEMDRAW

				case win.CDDS_ITEMPREPAINT:
					if nmlvcd.Nmcd.DwItemSpec%2 == 1 {
						/*if tv.hasDarkAltBGColor &&
							nmlvcd.Nmcd.UItemState&win.CDIS_HOT == 0 &&
							tv.SendMessage(win.LVM_GETITEMSTATE, nmlvcd.Nmcd.DwItemSpec, win.LVIS_SELECTED) == 0 &&
							int32(tv.SendMessage(win.LVM_GETSELECTEDCOLUMN, 0, 0)) != nmlvcd.ISubItem {
							fmt.Printf("selcol: %d, subitem: %d\n", int32(tv.SendMessage(win.LVM_GETSELECTEDCOLUMN, 0, 0)), nmlvcd.ISubItem)
							nmlvcd.ClrText = white
						}*/
						nmlvcd.ClrTextBk = win.COLORREF(tv.alternatingRowBGColor)
					}

					return win.CDRF_NOTIFYSUBITEMDRAW

				case win.CDDS_ITEMPREPAINT | win.CDDS_SUBITEM:
					if nmlvcd.Nmcd.DwItemSpec%2 == 1 &&
						tv.hasDarkAltBGColor &&
						nmlvcd.Nmcd.UItemState&win.CDIS_HOT == 0 &&
						tv.SendMessage(win.LVM_GETITEMSTATE, nmlvcd.Nmcd.DwItemSpec, win.LVIS_SELECTED) == 0 &&
						int32(tv.SendMessage(win.LVM_GETSELECTEDCOLUMN, 0, 0)) != nmlvcd.ISubItem {

						nmlvcd.ClrText = white
					}

					return win.CDRF_NEWFONT
				}
			}

			return win.CDRF_DODEFAULT

		case win.LVN_COLUMNCLICK:
			nmlv := (*win.NMLISTVIEW)(unsafe.Pointer(lParam))

			col := tv.fromLVColIdx(nmlv.ISubItem)

			if sorter, ok := tv.model.(Sorter); ok && sorter.ColumnSortable(col) {
				prevCol := sorter.SortedColumn()
				var order SortOrder
				if col != prevCol || sorter.SortOrder() == SortDescending {
					order = SortAscending
				} else {
					order = SortDescending
				}
				tv.sortedColumnIndex = col
				tv.sortOrder = order
				sorter.Sort(col, order)
			}

			tv.columnClickedPublisher.Publish(col)

		case win.LVN_ITEMCHANGED:
			nmlv := (*win.NMLISTVIEW)(unsafe.Pointer(lParam))
			selectedNow := nmlv.UNewState&win.LVIS_SELECTED > 0
			selectedBefore := nmlv.UOldState&win.LVIS_SELECTED > 0
			if selectedNow && !selectedBefore {
				tv.prevIndex = tv.currentIndex
				tv.currentIndex = int(nmlv.IItem)
				if tv.itemStateChangedEventDelay > 0 {
					tv.delayedCurrentIndexChangedCanceled = false
					if 0 == win.SetTimer(
						tv.hWnd,
						tableViewCurrentIndexChangedTimerId,
						uint32(tv.itemStateChangedEventDelay),
						0) {

						lastError("SetTimer")
					}
				} else {
					tv.currentIndexChangedPublisher.Publish()
				}
			}
			if !tv.SingleItemSelection() {
				tv.updateSelectedIndexes()
			}

		case win.LVN_ITEMACTIVATE:
			nmia := (*win.NMITEMACTIVATE)(unsafe.Pointer(lParam))

			if tv.itemStateChangedEventDelay > 0 {
				tv.delayedCurrentIndexChangedCanceled = true
			}

			if int(nmia.IItem) != tv.currentIndex {
				tv.SetCurrentIndex(int(nmia.IItem))
				tv.currentIndexChangedPublisher.Publish()
			}

			tv.itemActivatedPublisher.Publish()
		}

	case win.WM_TIMER:
		switch wParam {
		case tableViewCurrentIndexChangedTimerId:
			if !tv.delayedCurrentIndexChangedCanceled {
				tv.currentIndexChangedPublisher.Publish()
			}

		case tableViewSelectedIndexesChangedTimerId:
			tv.selectedIndexesChangedPublisher.Publish()
		}
	}

	return tv.WidgetBase.WndProc(hwnd, msg, wParam, lParam)
}