TextFieldSelectionDelegate.kt
/*
* 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.ui.text.TextLayoutResult
import androidx.compose.ui.text.TextRange
/**
* Return selection information for TextField.
*
* @param textLayoutResult a result of the text layout.
* @param rawStartOffset unprocessed start offset calculated directly from input position
* @param rawEndOffset unprocessed end offset calculated directly from input position
* @param previousSelection previous selection result
* @param isStartHandle true if the start handle is being dragged
* @param adjustment selection is adjusted according to this param
*
* @return selected text range.
*/
internal fun getTextFieldSelection(
textLayoutResult: TextLayoutResult?,
rawStartOffset: Int,
rawEndOffset: Int,
previousSelection: TextRange?,
isStartHandle: Boolean,
adjustment: SelectionAdjustment
): TextRange {
textLayoutResult?.let {
val textRange = TextRange(rawStartOffset, rawEndOffset)
// When the previous selection is null, it's allowed to have collapsed selection.
// So we can ignore the SelectionAdjustment.CHARACTER.
if (previousSelection == null && adjustment == SelectionAdjustment.CHARACTER) {
return textRange
}
return adjustSelection(
textLayoutResult = textLayoutResult,
textRange = textRange,
isStartHandle = isStartHandle,
previousHandlesCrossed = previousSelection?.reversed ?: false,
adjustment = adjustment
)
}
return TextRange(0, 0)
}