| /* |
| * Copyright 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.compose.foundation.text.selection |
| |
| import androidx.compose.foundation.text.DefaultCursorThickness |
| import androidx.compose.foundation.text.Handle |
| import androidx.compose.foundation.text.HandleState |
| import androidx.compose.foundation.text.InternalFoundationTextApi |
| import androidx.compose.foundation.text.TextDragObserver |
| import androidx.compose.foundation.text.TextFieldState |
| import androidx.compose.foundation.text.UndoManager |
| import androidx.compose.foundation.text.ValidatingEmptyOffsetMappingIdentity |
| import androidx.compose.foundation.text.detectDownAndDragGesturesWithObserver |
| import androidx.compose.runtime.Composable |
| import androidx.compose.runtime.getValue |
| import androidx.compose.runtime.mutableStateOf |
| import androidx.compose.runtime.remember |
| import androidx.compose.runtime.setValue |
| import androidx.compose.ui.Modifier |
| import androidx.compose.ui.focus.FocusRequester |
| import androidx.compose.ui.geometry.Offset |
| import androidx.compose.ui.geometry.Rect |
| import androidx.compose.ui.hapticfeedback.HapticFeedback |
| import androidx.compose.ui.hapticfeedback.HapticFeedbackType |
| import androidx.compose.ui.input.pointer.PointerEvent |
| import androidx.compose.ui.input.pointer.pointerInput |
| import androidx.compose.ui.platform.ClipboardManager |
| import androidx.compose.ui.platform.TextToolbar |
| import androidx.compose.ui.platform.TextToolbarStatus |
| import androidx.compose.ui.text.AnnotatedString |
| import androidx.compose.ui.text.TextRange |
| import androidx.compose.ui.text.input.OffsetMapping |
| import androidx.compose.ui.text.input.PasswordVisualTransformation |
| import androidx.compose.ui.text.input.TextFieldValue |
| import androidx.compose.ui.text.input.VisualTransformation |
| import androidx.compose.ui.text.input.getSelectedText |
| import androidx.compose.ui.text.input.getTextAfterSelection |
| import androidx.compose.ui.text.input.getTextBeforeSelection |
| import androidx.compose.ui.text.style.ResolvedTextDirection |
| import androidx.compose.ui.unit.Density |
| import androidx.compose.ui.unit.IntSize |
| import androidx.compose.ui.unit.dp |
| import kotlin.math.absoluteValue |
| import kotlin.math.max |
| import kotlin.math.min |
| |
| /** |
| * A bridge class between user interaction to the text field selection. |
| */ |
| internal class TextFieldSelectionManager( |
| val undoManager: UndoManager? = null |
| ) { |
| |
| /** |
| * The current [OffsetMapping] for text field. |
| */ |
| internal var offsetMapping: OffsetMapping = ValidatingEmptyOffsetMappingIdentity |
| |
| /** |
| * Called when the input service updates the values in [TextFieldValue]. |
| */ |
| internal var onValueChange: (TextFieldValue) -> Unit = {} |
| |
| /** |
| * The current [TextFieldState]. |
| */ |
| internal var state: TextFieldState? = null |
| |
| /** |
| * The current [TextFieldValue]. |
| */ |
| internal var value: TextFieldValue by mutableStateOf(TextFieldValue()) |
| |
| /** |
| * Visual transformation of the text field's text. Used to check if certain toolbar options |
| * are permitted. For example, 'cut' will not be available is it is password transformation. |
| */ |
| internal var visualTransformation: VisualTransformation = VisualTransformation.None |
| |
| /** |
| * [ClipboardManager] to perform clipboard features. |
| */ |
| internal var clipboardManager: ClipboardManager? = null |
| |
| /** |
| * [TextToolbar] to show floating toolbar(post-M) or primary toolbar(pre-M). |
| */ |
| var textToolbar: TextToolbar? = null |
| |
| /** |
| * [HapticFeedback] handle to perform haptic feedback. |
| */ |
| var hapticFeedBack: HapticFeedback? = null |
| |
| /** |
| * [FocusRequester] used to request focus for the TextField. |
| */ |
| var focusRequester: FocusRequester? = null |
| |
| /** |
| * Defines if paste and cut toolbar menu actions should be shown |
| */ |
| var editable by mutableStateOf(true) |
| |
| /** |
| * The beginning position of the drag gesture. Every time a new drag gesture starts, it wil be |
| * recalculated. |
| */ |
| private var dragBeginPosition = Offset.Zero |
| |
| /** |
| * The beginning offset of the drag gesture translated into position in text. Every time a |
| * new drag gesture starts, it wil be recalculated. |
| * Unlike [dragBeginPosition] that is relative to the decoration box, |
| * [dragBeginOffsetInText] represents index in text. Essentially, it is equal to |
| * `layoutResult.getOffsetForPosition(dragBeginPosition)`. |
| */ |
| private var dragBeginOffsetInText: Int? = null |
| |
| /** |
| * The total distance being dragged of the drag gesture. Every time a new drag gesture starts, |
| * it will be zeroed out. |
| */ |
| private var dragTotalDistance = Offset.Zero |
| |
| /** |
| * A flag to check if a selection or cursor handle is being dragged, and which handle is being |
| * dragged. |
| * If this value is non-null, then onPress will not select any text. |
| * This value will be set to non-null when either handle is being dragged, and be reset to null |
| * when the dragging is stopped. |
| */ |
| var draggingHandle: Handle? by mutableStateOf(null) |
| private set |
| |
| var currentDragPosition: Offset? by mutableStateOf(null) |
| private set |
| |
| /** |
| * The old [TextFieldValue] before entering the selection mode on long press. Used to exit |
| * the selection mode. |
| */ |
| private var oldValue: TextFieldValue = TextFieldValue() |
| |
| /** |
| * [TextDragObserver] for long press and drag to select in TextField. |
| */ |
| internal val touchSelectionObserver = object : TextDragObserver { |
| override fun onDown(point: Offset) { |
| // Not supported for long-press-drag. |
| } |
| |
| override fun onUp() { |
| // Nothing to do. |
| } |
| |
| override fun onStart(startPoint: Offset) { |
| if (draggingHandle != null) return |
| // While selecting by long-press-dragging, the "end" of the selection is always the one |
| // being controlled by the drag. |
| draggingHandle = Handle.SelectionEnd |
| |
| // ensuring that current action mode (selection toolbar) is invalidated |
| hideSelectionToolbar() |
| |
| // Long Press at the blank area, the cursor should show up at the end of the line. |
| if (state?.layoutResult?.isPositionOnText(startPoint) != true) { |
| state?.layoutResult?.let { layoutResult -> |
| val offset = offsetMapping.transformedToOriginal( |
| layoutResult.getLineEnd( |
| layoutResult.getLineForVerticalPosition(startPoint.y) |
| ) |
| ) |
| hapticFeedBack?.performHapticFeedback(HapticFeedbackType.TextHandleMove) |
| |
| val newValue = createTextFieldValue( |
| annotatedString = value.annotatedString, |
| selection = TextRange(offset, offset) |
| ) |
| enterSelectionMode() |
| onValueChange(newValue) |
| return |
| } |
| } |
| |
| // selection never started |
| if (value.text.isEmpty()) return |
| enterSelectionMode() |
| state?.layoutResult?.let { layoutResult -> |
| val offset = layoutResult.getOffsetForPosition(startPoint) |
| updateSelection( |
| value = value, |
| transformedStartOffset = offset, |
| transformedEndOffset = offset, |
| isStartHandle = false, |
| adjustment = SelectionAdjustment.Word |
| ) |
| dragBeginOffsetInText = offset |
| } |
| dragBeginPosition = startPoint |
| currentDragPosition = dragBeginPosition |
| dragTotalDistance = Offset.Zero |
| } |
| |
| override fun onDrag(delta: Offset) { |
| // selection never started, did not consume any drag |
| if (value.text.isEmpty()) return |
| |
| dragTotalDistance += delta |
| state?.layoutResult?.let { layoutResult -> |
| currentDragPosition = dragBeginPosition + dragTotalDistance |
| val startOffset = dragBeginOffsetInText ?: layoutResult.getOffsetForPosition( |
| position = dragBeginPosition, |
| coerceInVisibleBounds = false |
| ) |
| val endOffset = layoutResult.getOffsetForPosition( |
| position = currentDragPosition!!, |
| coerceInVisibleBounds = false |
| ) |
| updateSelection( |
| value = value, |
| transformedStartOffset = startOffset, |
| transformedEndOffset = endOffset, |
| isStartHandle = false, |
| adjustment = SelectionAdjustment.Word |
| ) |
| } |
| state?.showFloatingToolbar = false |
| } |
| |
| override fun onStop() { |
| draggingHandle = null |
| currentDragPosition = null |
| state?.showFloatingToolbar = true |
| if (textToolbar?.status == TextToolbarStatus.Hidden) showSelectionToolbar() |
| dragBeginOffsetInText = null |
| } |
| |
| override fun onCancel() {} |
| } |
| |
| internal val mouseSelectionObserver = object : MouseSelectionObserver { |
| override fun onExtend(downPosition: Offset): Boolean { |
| state?.layoutResult?.let { layoutResult -> |
| val startOffset = offsetMapping.originalToTransformed(value.selection.start) |
| val clickOffset = layoutResult.getOffsetForPosition(downPosition) |
| updateSelection( |
| value = value, |
| transformedStartOffset = startOffset, |
| transformedEndOffset = clickOffset, |
| isStartHandle = false, |
| adjustment = SelectionAdjustment.None |
| ) |
| return true |
| } |
| return false |
| } |
| |
| override fun onExtendDrag(dragPosition: Offset): Boolean { |
| if (value.text.isEmpty()) return false |
| |
| state?.layoutResult?.let { layoutResult -> |
| val startOffset = offsetMapping.originalToTransformed(value.selection.start) |
| val dragOffset = |
| layoutResult.getOffsetForPosition( |
| position = dragPosition, |
| coerceInVisibleBounds = false |
| ) |
| |
| updateSelection( |
| value = value, |
| transformedStartOffset = startOffset, |
| transformedEndOffset = dragOffset, |
| isStartHandle = false, |
| adjustment = SelectionAdjustment.None |
| ) |
| return true |
| } |
| return false |
| } |
| |
| override fun onStart( |
| downPosition: Offset, |
| adjustment: SelectionAdjustment |
| ): Boolean { |
| focusRequester?.requestFocus() |
| |
| dragBeginPosition = downPosition |
| |
| state?.layoutResult?.let { layoutResult -> |
| dragBeginOffsetInText = layoutResult.getOffsetForPosition(downPosition) |
| val clickOffset = layoutResult.getOffsetForPosition(dragBeginPosition) |
| updateSelection( |
| value = value, |
| transformedStartOffset = clickOffset, |
| transformedEndOffset = clickOffset, |
| isStartHandle = false, |
| adjustment = adjustment |
| ) |
| return true |
| } |
| return false |
| } |
| |
| override fun onDrag(dragPosition: Offset, adjustment: SelectionAdjustment): Boolean { |
| if (value.text.isEmpty()) return false |
| |
| state?.layoutResult?.let { layoutResult -> |
| val dragOffset = |
| layoutResult.getOffsetForPosition( |
| position = dragPosition, |
| coerceInVisibleBounds = false |
| ) |
| |
| updateSelection( |
| value = value, |
| transformedStartOffset = dragBeginOffsetInText!!, |
| transformedEndOffset = dragOffset, |
| isStartHandle = false, |
| adjustment = adjustment |
| ) |
| return true |
| } |
| return false |
| } |
| } |
| |
| /** |
| * [TextDragObserver] for dragging the selection handles to change the selection in TextField. |
| */ |
| internal fun handleDragObserver(isStartHandle: Boolean): TextDragObserver = |
| object : TextDragObserver { |
| override fun onDown(point: Offset) { |
| draggingHandle = if (isStartHandle) Handle.SelectionStart else Handle.SelectionEnd |
| currentDragPosition = getAdjustedCoordinates(getHandlePosition(isStartHandle)) |
| } |
| |
| override fun onUp() { |
| draggingHandle = null |
| currentDragPosition = null |
| } |
| |
| override fun onStart(startPoint: Offset) { |
| // The position of the character where the drag gesture should begin. This is in |
| // the composable coordinates. |
| dragBeginPosition = getAdjustedCoordinates(getHandlePosition(isStartHandle)) |
| currentDragPosition = dragBeginPosition |
| // Zero out the total distance that being dragged. |
| dragTotalDistance = Offset.Zero |
| draggingHandle = if (isStartHandle) Handle.SelectionStart else Handle.SelectionEnd |
| state?.showFloatingToolbar = false |
| } |
| |
| override fun onDrag(delta: Offset) { |
| dragTotalDistance += delta |
| |
| state?.layoutResult?.value?.let { layoutResult -> |
| currentDragPosition = dragBeginPosition + dragTotalDistance |
| val startOffset = if (isStartHandle) { |
| layoutResult.getOffsetForPosition(currentDragPosition!!) |
| } else { |
| offsetMapping.originalToTransformed(value.selection.start) |
| } |
| |
| val endOffset = if (isStartHandle) { |
| offsetMapping.originalToTransformed(value.selection.end) |
| } else { |
| layoutResult.getOffsetForPosition(currentDragPosition!!) |
| } |
| |
| updateSelection( |
| value = value, |
| transformedStartOffset = startOffset, |
| transformedEndOffset = endOffset, |
| isStartHandle = isStartHandle, |
| adjustment = SelectionAdjustment.Character |
| ) |
| } |
| state?.showFloatingToolbar = false |
| } |
| |
| override fun onStop() { |
| draggingHandle = null |
| currentDragPosition = null |
| state?.showFloatingToolbar = true |
| if (textToolbar?.status == TextToolbarStatus.Hidden) showSelectionToolbar() |
| } |
| |
| override fun onCancel() {} |
| } |
| |
| /** |
| * [TextDragObserver] for dragging the cursor to change the selection in TextField. |
| */ |
| internal fun cursorDragObserver(): TextDragObserver = object : TextDragObserver { |
| override fun onDown(point: Offset) { |
| draggingHandle = Handle.Cursor |
| currentDragPosition = getAdjustedCoordinates(getHandlePosition(true)) |
| } |
| |
| override fun onUp() { |
| draggingHandle = null |
| currentDragPosition = null |
| } |
| |
| override fun onStart(startPoint: Offset) { |
| // The position of the character where the drag gesture should begin. This is in |
| // the composable coordinates. |
| dragBeginPosition = getAdjustedCoordinates(getHandlePosition(true)) |
| currentDragPosition = dragBeginPosition |
| // Zero out the total distance that being dragged. |
| dragTotalDistance = Offset.Zero |
| draggingHandle = Handle.Cursor |
| } |
| |
| override fun onDrag(delta: Offset) { |
| dragTotalDistance += delta |
| |
| state?.layoutResult?.value?.let { layoutResult -> |
| currentDragPosition = dragBeginPosition + dragTotalDistance |
| val offset = offsetMapping.transformedToOriginal( |
| layoutResult.getOffsetForPosition(currentDragPosition!!) |
| ) |
| |
| val newSelection = TextRange(offset, offset) |
| |
| // Nothing changed, skip onValueChange hand hapticFeedback. |
| if (newSelection == value.selection) return |
| |
| hapticFeedBack?.performHapticFeedback(HapticFeedbackType.TextHandleMove) |
| onValueChange( |
| createTextFieldValue( |
| annotatedString = value.annotatedString, |
| selection = newSelection |
| ) |
| ) |
| } |
| } |
| |
| override fun onStop() { |
| draggingHandle = null |
| currentDragPosition = null |
| } |
| |
| override fun onCancel() {} |
| } |
| |
| /** |
| * The method to record the required state values on entering the selection mode. |
| * |
| * Is triggered on long press or accessibility action. |
| */ |
| internal fun enterSelectionMode() { |
| if (state?.hasFocus == false) { |
| focusRequester?.requestFocus() |
| } |
| oldValue = value |
| state?.showFloatingToolbar = true |
| setHandleState(HandleState.Selection) |
| } |
| |
| /** |
| * The method to record the corresponding state values on exiting the selection mode. |
| * |
| * Is triggered on accessibility action. |
| */ |
| internal fun exitSelectionMode() { |
| state?.showFloatingToolbar = false |
| setHandleState(HandleState.None) |
| } |
| |
| internal fun deselect(position: Offset? = null) { |
| if (!value.selection.collapsed) { |
| // if selection was not collapsed, set a default cursor location, otherwise |
| // don't change the location of the cursor. |
| val layoutResult = state?.layoutResult |
| val newCursorOffset = if (position != null && layoutResult != null) { |
| offsetMapping.transformedToOriginal( |
| layoutResult.getOffsetForPosition(position) |
| ) |
| } else { |
| value.selection.max |
| } |
| val newValue = value.copy(selection = TextRange(newCursorOffset)) |
| onValueChange(newValue) |
| } |
| |
| // If a new cursor position is given and the text is not empty, enter the |
| // HandleState.Cursor state. |
| val selectionMode = if (position != null && value.text.isNotEmpty()) { |
| HandleState.Cursor |
| } else { |
| HandleState.None |
| } |
| setHandleState(selectionMode) |
| hideSelectionToolbar() |
| } |
| |
| /** |
| * The method for copying text. |
| * |
| * If there is no selection, return. |
| * Put the selected text into the [ClipboardManager], and cancel the selection, if |
| * [cancelSelection] is true. |
| * The text in the text field should be unchanged. |
| * If [cancelSelection] is true, the new cursor offset should be at the end of the previous |
| * selected text. |
| */ |
| internal fun copy(cancelSelection: Boolean = true) { |
| if (value.selection.collapsed) return |
| |
| // TODO(b/171947959) check if original or transformed should be copied |
| clipboardManager?.setText(value.getSelectedText()) |
| |
| if (!cancelSelection) return |
| |
| val newCursorOffset = value.selection.max |
| val newValue = createTextFieldValue( |
| annotatedString = value.annotatedString, |
| selection = TextRange(newCursorOffset, newCursorOffset) |
| ) |
| onValueChange(newValue) |
| setHandleState(HandleState.None) |
| } |
| |
| /** |
| * The method for pasting text. |
| * |
| * Get the text from [ClipboardManager]. If it's null, return. |
| * The new text should be the text before the selected text, plus the text from the |
| * [ClipboardManager], and plus the text after the selected text. |
| * Then the selection should collapse, and the new cursor offset should be the end of the |
| * newly added text. |
| */ |
| internal fun paste() { |
| val text = clipboardManager?.getText() ?: return |
| |
| val newText = value.getTextBeforeSelection(value.text.length) + |
| text + |
| value.getTextAfterSelection(value.text.length) |
| val newCursorOffset = value.selection.min + text.length |
| |
| val newValue = createTextFieldValue( |
| annotatedString = newText, |
| selection = TextRange(newCursorOffset, newCursorOffset) |
| ) |
| onValueChange(newValue) |
| setHandleState(HandleState.None) |
| undoManager?.forceNextSnapshot() |
| } |
| |
| /** |
| * The method for cutting text. |
| * |
| * If there is no selection, return. |
| * Put the selected text into the [ClipboardManager]. |
| * The new text should be the text before the selection plus the text after the selection. |
| * And the new cursor offset should be between the text before the selection, and the text |
| * after the selection. |
| */ |
| internal fun cut() { |
| if (value.selection.collapsed) return |
| |
| // TODO(b/171947959) check if original or transformed should be cut |
| clipboardManager?.setText(value.getSelectedText()) |
| |
| val newText = value.getTextBeforeSelection(value.text.length) + |
| value.getTextAfterSelection(value.text.length) |
| val newCursorOffset = value.selection.min |
| |
| val newValue = createTextFieldValue( |
| annotatedString = newText, |
| selection = TextRange(newCursorOffset, newCursorOffset) |
| ) |
| onValueChange(newValue) |
| setHandleState(HandleState.None) |
| undoManager?.forceNextSnapshot() |
| } |
| |
| /*@VisibleForTesting*/ |
| internal fun selectAll() { |
| val newValue = createTextFieldValue( |
| annotatedString = value.annotatedString, |
| selection = TextRange(0, value.text.length) |
| ) |
| onValueChange(newValue) |
| oldValue = oldValue.copy(selection = newValue.selection) |
| state?.showFloatingToolbar = true |
| } |
| |
| internal fun getHandlePosition(isStartHandle: Boolean): Offset { |
| val offset = if (isStartHandle) value.selection.start else value.selection.end |
| return getSelectionHandleCoordinates( |
| textLayoutResult = state?.layoutResult!!.value, |
| offset = offsetMapping.originalToTransformed(offset), |
| isStart = isStartHandle, |
| areHandlesCrossed = value.selection.reversed |
| ) |
| } |
| |
| internal fun getCursorPosition(density: Density): Offset { |
| val offset = offsetMapping.originalToTransformed(value.selection.start) |
| val layoutResult = state?.layoutResult!!.value |
| val cursorRect = layoutResult.getCursorRect( |
| offset.coerceIn(0, layoutResult.layoutInput.text.length) |
| ) |
| val x = with(density) { |
| cursorRect.left + DefaultCursorThickness.toPx() / 2 |
| } |
| return Offset(x, cursorRect.bottom) |
| } |
| |
| /** |
| * This function get the selected region as a Rectangle region, and pass it to [TextToolbar] |
| * to make the FloatingToolbar show up in the proper place. In addition, this function passes |
| * the copy, paste and cut method as callbacks when "copy", "cut" or "paste" is clicked. |
| */ |
| internal fun showSelectionToolbar() { |
| val isPassword = visualTransformation is PasswordVisualTransformation |
| val copy: (() -> Unit)? = if (!value.selection.collapsed && !isPassword) { |
| { |
| copy() |
| hideSelectionToolbar() |
| } |
| } else null |
| |
| val cut: (() -> Unit)? = if (!value.selection.collapsed && editable && !isPassword) { |
| { |
| cut() |
| hideSelectionToolbar() |
| } |
| } else null |
| |
| val paste: (() -> Unit)? = if (editable && clipboardManager?.hasText() == true) { |
| { |
| paste() |
| hideSelectionToolbar() |
| } |
| } else null |
| |
| val selectAll: (() -> Unit)? = if (value.selection.length != value.text.length) { |
| { |
| selectAll() |
| } |
| } else null |
| |
| textToolbar?.showMenu( |
| rect = getContentRect(), |
| onCopyRequested = copy, |
| onPasteRequested = paste, |
| onCutRequested = cut, |
| onSelectAllRequested = selectAll |
| ) |
| } |
| |
| internal fun hideSelectionToolbar() { |
| if (textToolbar?.status == TextToolbarStatus.Shown) { |
| textToolbar?.hide() |
| } |
| } |
| |
| fun contextMenuOpenAdjustment(position: Offset) { |
| state?.layoutResult?.let { layoutResult -> |
| val offset = layoutResult.getOffsetForPosition(position) |
| if (!value.selection.contains(offset)) { |
| updateSelection( |
| value = value, |
| transformedStartOffset = offset, |
| transformedEndOffset = offset, |
| isStartHandle = false, |
| adjustment = SelectionAdjustment.Word |
| ) |
| } |
| } |
| } |
| |
| /** |
| * Check if the text in the text field changed. |
| * When the content in the text field is modified, this method returns true. |
| */ |
| internal fun isTextChanged(): Boolean { |
| return oldValue.text != value.text |
| } |
| |
| /** |
| * Calculate selected region as [Rect]. The top is the top of the first selected |
| * line, and the bottom is the bottom of the last selected line. The left is the leftmost |
| * handle's horizontal coordinates, and the right is the rightmost handle's coordinates. |
| */ |
| @OptIn(InternalFoundationTextApi::class) |
| private fun getContentRect(): Rect { |
| state?.let { |
| val startOffset = |
| state?.layoutCoordinates?.localToRoot(getHandlePosition(true)) ?: Offset.Zero |
| val endOffset = |
| state?.layoutCoordinates?.localToRoot(getHandlePosition(false)) ?: Offset.Zero |
| val startTop = |
| state?.layoutCoordinates?.localToRoot( |
| Offset( |
| 0f, |
| it.layoutResult?.value?.getCursorRect( |
| value.selection.start.coerceIn( |
| 0, |
| max(0, value.text.length - 1) |
| ) |
| )?.top ?: 0f |
| ) |
| )?.y ?: 0f |
| val endTop = |
| state?.layoutCoordinates?.localToRoot( |
| Offset( |
| 0f, |
| it.layoutResult?.value?.getCursorRect( |
| value.selection.end.coerceIn( |
| 0, |
| max(0, value.text.length - 1) |
| ) |
| )?.top ?: 0f |
| ) |
| )?.y ?: 0f |
| |
| val left = min(startOffset.x, endOffset.x) |
| val right = max(startOffset.x, endOffset.x) |
| val top = min(startTop, endTop) |
| val bottom = max(startOffset.y, endOffset.y) + |
| 25.dp.value * it.textDelegate.density.density |
| |
| return Rect(left, top, right, bottom) |
| } |
| |
| return Rect.Zero |
| } |
| |
| private fun updateSelection( |
| value: TextFieldValue, |
| transformedStartOffset: Int, |
| transformedEndOffset: Int, |
| isStartHandle: Boolean, |
| adjustment: SelectionAdjustment |
| ) { |
| val transformedSelection = TextRange( |
| offsetMapping.originalToTransformed(value.selection.start), |
| offsetMapping.originalToTransformed(value.selection.end) |
| ) |
| |
| val newTransformedSelection = getTextFieldSelection( |
| textLayoutResult = state?.layoutResult?.value, |
| rawStartOffset = transformedStartOffset, |
| rawEndOffset = transformedEndOffset, |
| previousSelection = if (transformedSelection.collapsed) null else transformedSelection, |
| isStartHandle = isStartHandle, |
| adjustment = adjustment |
| ) |
| |
| val originalSelection = TextRange( |
| start = offsetMapping.transformedToOriginal(newTransformedSelection.start), |
| end = offsetMapping.transformedToOriginal(newTransformedSelection.end) |
| ) |
| |
| if (originalSelection == value.selection) return |
| |
| hapticFeedBack?.performHapticFeedback(HapticFeedbackType.TextHandleMove) |
| |
| val newValue = createTextFieldValue( |
| annotatedString = value.annotatedString, |
| selection = originalSelection |
| ) |
| onValueChange(newValue) |
| |
| // showSelectionHandleStart/End might be set to false when scrolled out of the view. |
| // When the selection is updated, they must also be updated so that handles will be shown |
| // or hidden correctly. |
| state?.showSelectionHandleStart = isSelectionHandleInVisibleBound(true) |
| state?.showSelectionHandleEnd = isSelectionHandleInVisibleBound(false) |
| } |
| |
| private fun setHandleState(handleState: HandleState) { |
| state?.let { it.handleState = handleState } |
| } |
| |
| private fun createTextFieldValue( |
| annotatedString: AnnotatedString, |
| selection: TextRange |
| ): TextFieldValue { |
| return TextFieldValue( |
| annotatedString = annotatedString, |
| selection = selection |
| ) |
| } |
| } |
| |
| @Composable |
| internal fun TextFieldSelectionHandle( |
| isStartHandle: Boolean, |
| direction: ResolvedTextDirection, |
| manager: TextFieldSelectionManager |
| ) { |
| val observer = remember(isStartHandle, manager) { |
| manager.handleDragObserver(isStartHandle) |
| } |
| val position = manager.getHandlePosition(isStartHandle) |
| |
| SelectionHandle( |
| position = position, |
| isStartHandle = isStartHandle, |
| direction = direction, |
| handlesCrossed = manager.value.selection.reversed, |
| modifier = Modifier.pointerInput(observer) { |
| detectDownAndDragGesturesWithObserver(observer) |
| }, |
| content = null |
| ) |
| } |
| |
| /** |
| * Whether the selection handle is in the visible bound of the TextField. |
| */ |
| internal fun TextFieldSelectionManager.isSelectionHandleInVisibleBound( |
| isStartHandle: Boolean |
| ): Boolean = state?.layoutCoordinates?.visibleBounds()?.containsInclusive( |
| getHandlePosition(isStartHandle) |
| ) ?: false |
| |
| // TODO(b/180075467) it should be part of PointerEvent API in one way or another |
| internal expect val PointerEvent.isShiftPressed: Boolean |
| |
| /** |
| * Optionally shows a magnifier widget, if the current platform supports it, for the current state |
| * of a [TextFieldSelectionManager]. Should check [TextFieldSelectionManager.draggingHandle] to see |
| * which handle is being dragged and then calculate the magnifier position for that handle. |
| * |
| * Actual implementations should as much as possible actually live in this common source set, _not_ |
| * the platform-specific source sets. The actual implementations of this function should then just |
| * delegate to those functions. |
| */ |
| internal expect fun Modifier.textFieldMagnifier(manager: TextFieldSelectionManager): Modifier |
| |
| internal fun calculateSelectionMagnifierCenterAndroid( |
| manager: TextFieldSelectionManager, |
| magnifierSize: IntSize |
| ): Offset { |
| // Never show the magnifier in an empty text field. |
| if (manager.value.text.isEmpty()) return Offset.Unspecified |
| val rawTextOffset = when (manager.draggingHandle) { |
| null -> return Offset.Unspecified |
| Handle.Cursor, |
| Handle.SelectionStart -> manager.value.selection.start |
| Handle.SelectionEnd -> manager.value.selection.end |
| } |
| val textOffset = manager.offsetMapping.originalToTransformed(rawTextOffset) |
| .coerceIn(manager.value.text.indices) |
| val layoutResult = manager.state?.layoutResult?.value ?: return Offset.Unspecified |
| // Center vertically on the current line. |
| // If the text hasn't been laid out yet, don't show the modifier. |
| val offsetCenter = layoutResult.getBoundingBox(textOffset).center |
| |
| val containerCoordinates = manager.state?.layoutCoordinates ?: return Offset.Unspecified |
| val fieldCoordinates = |
| manager.state?.layoutResult?.innerTextFieldCoordinates ?: return Offset.Unspecified |
| val localDragPosition = manager.currentDragPosition?.let { |
| fieldCoordinates.localPositionOf(containerCoordinates, it) |
| } ?: return Offset.Unspecified |
| val dragX = localDragPosition.x |
| val line = layoutResult.getLineForOffset(textOffset) |
| val lineStartOffset = layoutResult.getLineStart(line) |
| val lineEndOffset = layoutResult.getLineEnd(line, visibleEnd = true) |
| val areHandlesCrossed = manager.value.selection.start > manager.value.selection.end |
| val lineStart = layoutResult.getHorizontalPosition( |
| lineStartOffset, |
| isStart = true, |
| areHandlesCrossed = areHandlesCrossed |
| ) |
| val lineEnd = layoutResult.getHorizontalPosition( |
| lineEndOffset, |
| isStart = false, |
| areHandlesCrossed = areHandlesCrossed |
| ) |
| val lineMin = minOf(lineStart, lineEnd) |
| val lineMax = maxOf(lineStart, lineEnd) |
| val centerX = dragX.coerceIn(lineMin, lineMax) |
| |
| // Hide the magnifier when dragged too far (outside the horizontal bounds of how big the |
| // magnifier actually is). See |
| // https://cs.android.com/android/platform/superproject/+/master:frameworks/base/core/java/android/widget/Editor.java;l=5228-5231;drc=2fdb6bd709be078b72f011334362456bb758922c |
| if ((dragX - centerX).absoluteValue > magnifierSize.width / 2) { |
| return Offset.Unspecified |
| } |
| |
| return containerCoordinates.localPositionOf( |
| fieldCoordinates, |
| Offset(centerX, offsetCenter.y) |
| ) |
| } |
