ListView.qml

import QtQuick
import QtQuick.Controls

import EasyApplication.Gui.Globals as EaGlobals
import EasyApplication.Gui.Style as EaStyle
import EasyApplication.Gui.Animations as EaAnimations
import EasyApplication.Gui.Elements as EaElements
import EasyApplication.Gui.Components as EaComponents

ListView {
    id: listView

    // ── Public API ──────────────────────────────────────────────────────
    // Properties and functions for consumers instantiating this component.

    width: EaStyle.Sizes.sideBarContentWidth

    // When true, rows use 1.5x height.
    property bool tallRows: false

    // Max visible rows before scrolling kicks in.
    property int maxRowCountShow: EaStyle.Sizes.tableMaxRowCountShow

    // Text shown when ListView model is empty.
    property alias defaultInfoText: defaultInfoLabel.text

    // ScrollBar.AsNeeded / ScrollBar.AlwaysOff / ScrollBar.AlwaysOn
    property int scrollBarPolicy: ScrollBar.AsNeeded

    // false = indicator style: thin, non-draggable, shows only while scrolling
    property bool scrollBarInteractive: true

    // When false, clicks never modify the selection model. Use for lists
    // with inline editors but no row-level selection concept.
    property bool selectable: true

    // Allow ctrl/shift multi-select.
    property bool multiSelection: true

    // When false, clicking a cell editor (TextInput) does not select the row.
    // Editing and selection remain orthogonal.
    property bool selectOnEdit: false

    // Claim the enclosing FocusScope's default focus target.
    focus: true

    // Whether the row highlight stays lit. Default true (always). Bind to a
    // focus expression (e.g. `myScope.activeFocus`) to dim when focus leaves
    // that scope.
    property bool selectionActive: true

    // Column widths definition. Each entry is one of:
    //   positive int  — fixed width in pixels.
    //   EaStyle.Sizes.tableColumnFlex (-1) — fill remaining row width.
    //                  Multiple flex columns split the leftover space evenly.
    //   EaStyle.Sizes.tableColumnAuto  (0) — fit the header label's implicit
    //                  text width plus autoColumnPadding. Requires a header
    //                  delegate (ListViewHeader) so the resolver has a label
    //                  to measure; falls back to 0 if header not yet ready.
    // Example: columnWidths: [40, EaStyle.Sizes.tableColumnFlex, EaStyle.Sizes.tableColumnAuto, 100]
    property var columnWidths: []

    // Padding added to each tableColumnAuto column on top of the measured
    // header text width. Defaults to 2x tableColumnSpacing — same breathing
    // room as a typical hand-tuned column.
    property real autoColumnPadding: EaStyle.Sizes.tableColumnSpacing * 2

    // Horizontal padding inside each row (header + delegate). Subtracted from
    // flex-column budget so flex columns don't overflow the row.
    property real rowPadding: EaStyle.Sizes.tableColumnSpacing

    // Clear all selection and reset anchor.
    function clearSelection() {
        selectionModel.clearSelection()
        anchorRow = -1
    }

    // Release any cell editor that currently owns focus inside the list.
    // Forces focus to a non-FocusScope sibling so the editScope's inner
    // focus chain is broken at the listView level — `forceActiveFocus()`
    // on listView itself would re-confirm the existing chain instead.
    function endEditing() {
        focusSink.forceActiveFocus()
    }

    // ── Companion API ───────────────────────────────────────────────────
    // Used by ListViewHeader and ListViewDelegate. Not intended for direct consumer use.

    // Anchor row index for shift-selection range tracking.
    // Used by: ListViewDelegate (anchor indicator when row is not selected)
    property int anchorRow: -1
    onCountChanged: if (anchorRow >= count) anchorRow = -1

    // Row height in px, derived from tallRows.
    // Used by: ListViewDelegate (implicitHeight), ListViewHeader (own height)
    property int tableRowHeight: tallRows ?
                                     1.5 * EaStyle.Sizes.tableRowHeight :
                                     EaStyle.Sizes.tableRowHeight

    // Current selection state.
    // Used by: ListViewDelegate (binding dependency for row color)
    readonly property var selectedIndexes: selectionModel.selectedIndexes

    // Computed px widths from columnWidths.
    // Used by: ListViewHeader + ListViewDelegate (subscribe via onResolvedColumnWidthsChanged)
    //
    // Two-pass resolution:
    //   1. tableColumnAuto (0)  → header child implicitWidth + autoColumnPadding.
    //   2. tableColumnFlex (-1) → split leftover row width evenly.
    readonly property var resolvedColumnWidths: {
        if (!columnWidths.length) return []

        // Pass 1: resolve auto columns from header implicit widths.
        const headerWidths = (headerItem && headerItem.implicitColumnWidths) || []
        let widths = columnWidths.map((w, i) => {
            if (w === EaStyle.Sizes.tableColumnAuto && i < headerWidths.length)
                return headerWidths[i] + autoColumnPadding
            return w
        })

        // Pass 2: distribute remainder among flex columns.
        let fixed = 0, flexCount = 0
        for (let w of widths) {
            if (w > 0) fixed += w
            else flexCount++
        }
        const spacing = EaStyle.Sizes.tableColumnSpacing * (widths.length - 1)
        const border = EaStyle.Sizes.borderThickness * 2
        const fill = flexCount > 0 ? Math.max(0, (width - fixed - spacing - border - rowPadding * 2) / flexCount) : 0
        return widths.map(w => w > 0 ? w : fill)
    }

    // Apply resolvedColumnWidths to children of a Row item.
    // Used by: ListViewHeader + ListViewDelegate (onCompleted + onResolvedColumnWidthsChanged)
    function applyWidths(row) {
        for (let i = 0; i < row.children.length && i < resolvedColumnWidths.length; i++)
            row.children[i].width = resolvedColumnWidths[i]
    }

    // Check if given row index is selected.
    // Used by: ListViewDelegate (row background color)
    function isSelected(row) {
        let idx = _index(row)
        return idx && idx.valid ? selectionModel.isSelected(idx) : false
    }

    // Select row with ctrl/shift modifier logic.
    // Used by: ListViewDelegate (MouseArea.onClicked)
    function selectWithModifiers(row, modifiers) {
        if (!selectable) return
        let idx = _index(row)
        if (!idx) return

        // SHIFT: range selection
        if (listView.multiSelection && modifiers & Qt.ShiftModifier) {
            if (anchorRow < 0) {
                anchorRow = row
            }

            let savedAnchor = anchorRow
            let from = Math.min(anchorRow, row)
            let to = Math.max(anchorRow, row)

            if (!(modifiers & Qt.ControlModifier)) {
                selectionModel.clearSelection()
            }

            for (let i = from; i <= to; i++) {
                let rIdx = _index(i)
                if (rIdx) {
                    selectionModel.select(
                        rIdx,
                        ItemSelectionModel.Select | ItemSelectionModel.Rows
                    )
                }
            }

            anchorRow = savedAnchor
            return
        }

        // CTRL: toggle. Multi mode: add/remove from existing selection.
        // Single mode: deselect same row, or replace selection with new row.
        if (modifiers & Qt.ControlModifier) {
            if (listView.multiSelection) {
                selectionModel.select(idx, ItemSelectionModel.Toggle | ItemSelectionModel.Rows)
                anchorRow = row
                return
            }
            if (selectionModel.isSelected(idx)) {
                selectionModel.clearSelection()
                anchorRow = -1
            } else {
                selectionModel.select(idx, ItemSelectionModel.ClearAndSelect | ItemSelectionModel.Rows)
                anchorRow = row
            }
            return
        }

        // DEFAULT: single selection
        selectionModel.select(
            idx,
            ItemSelectionModel.ClearAndSelect | ItemSelectionModel.Rows
        )
        anchorRow = row
    }

    // ── Internals ───────────────────────────────────────────────────────

    // Convert row int to QModelIndex for selectionModel.
    function _index(row) {
        if (!selectionModel.model || row < 0 || row >= count)
            return null
        return selectionModel.model.index(row, 0)
    }

    // Fixes clicks not registering right after scroll.
    pressDelay: 10

    property bool hasMoreRows: count > maxRowCountShow
    property real visibleRowCount: hasMoreRows ? maxRowCountShow + 0.5 : count
    // headerItem is non-null when a header delegate is set (e.g. ListViewHeader).
    // Uses actual headerItem.height so custom headers with different heights work.
    property real _headerHeight: headerItem ? headerItem.height : 0
    height: count === 0
                ? 2 * EaStyle.Sizes.tableRowHeight
                : tableRowHeight * visibleRowCount + _headerHeight

    clip: true
    headerPositioning: ListView.OverlayHeader
    boundsBehavior: Flickable.StopAtBounds
    enabled: count > 0

    ScrollBar.vertical: EaElements.ScrollBar {
        policy: listView.scrollBarPolicy
        interactive: listView.scrollBarInteractive
        topInset: listView._headerHeight
        topPadding: listView._headerHeight
    }

    // Empty-state label.
    Rectangle {
        parent: listView
        visible: listView.count === 0
        width: listView.width
        height: EaStyle.Sizes.tableRowHeight * 2
        color: EaStyle.Colors.themeBackground

        Behavior on color { EaAnimations.ThemeChange {} }

        EaElements.Label {
            id: defaultInfoLabel

            anchors.verticalCenter: parent.verticalCenter
            leftPadding: EaStyle.Sizes.fontPixelSize
        }
    }

    // Table border, z above all content.
    Rectangle {
        parent: listView
        z: 4
        anchors.fill: parent
        color: "transparent"
        // Fixes disappearing border lines
        antialiasing: true
        border.color: EaStyle.Colors.appBarComboBoxBorder
        Behavior on border.color { EaAnimations.ThemeChange {} }
    }

    ItemSelectionModel {
        id: selectionModel
        model: listView.model

        onSelectionChanged: {
            if (selectedIndexes.length === 0)
                listView.anchorRow = -1
        }
    }

    // Sink target for endEditing(). Non-FocusScope child of listView, so
    // forceActiveFocus on it rewrites listView.focusedChild and breaks any
    // delegate's editScope chain — which forceActiveFocus on listView itself
    // cannot do (re-confirms the existing chain instead).
    Item {
        id: focusSink
        parent: listView
    }
}