| /* |
| * Copyright 2019 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.ui.text.selection |
| |
| import androidx.ui.geometry.Rect |
| import androidx.ui.unit.PxPosition |
| |
| /** |
| * The enum class allows user to decide the selection mode. |
| */ |
| internal enum class SelectionMode { |
| /** |
| * When selection handles are dragged across composables, selection extends by row, for example, |
| * when the end selection handle is dragged down, upper rows will be selected first, and the |
| * lower rows. |
| */ |
| Vertical { |
| override fun isSelected( |
| bounds: Rect, |
| start: PxPosition, |
| end: PxPosition |
| ): Boolean { |
| // When the end of the selection is above the top of the composable, the composable is outside |
| // of the selection range. |
| if (end.y < bounds.top) return false |
| |
| // When the end of the selection is on the left of the composable, and not below the bottom |
| // of composable, the composable is outside of the selection range. |
| if (end.x < bounds.left && end.y < bounds.bottom) return false |
| |
| // When the start of the selection is below the bottom of the composable, the composable is |
| // outside of the selection range. |
| if (start.y >= bounds.bottom) return false |
| |
| // When the start of the selection is on the right of the composable, and not above the top |
| // of the composable, the composable is outside of the selection range. |
| if (start.x >= bounds.right && start.y >= bounds.top) return false |
| |
| return true |
| } |
| |
| override fun areHandlesCrossed( |
| bounds: Rect, |
| start: PxPosition, |
| end: PxPosition |
| ): Boolean { |
| if (start.y >= bounds.top && start.y < bounds.bottom && |
| end.y >= bounds.top && end.y < bounds.bottom |
| ) { |
| // When the start and end of the selection are in the same row of widgets, check if |
| // x coordinates of the start and end are crossed each other. |
| return start.x > end.x |
| } else { |
| // When the start and end of the selection are not in the same row of widgets, check |
| // if y coordinates of the start and end are crossed each other. |
| return start.y > end.y |
| } |
| } |
| }, |
| |
| /** |
| * When selection handles are dragged across composables, selection extends by column, for example, |
| * when the end selection handle is dragged to the right, left columns will be selected first, |
| * and the right rows. |
| */ |
| Horizontal { |
| override fun isSelected( |
| bounds: Rect, |
| start: PxPosition, |
| end: PxPosition |
| ): Boolean { |
| // When the end of the selection is on the left of the composable, the composable is outside of |
| // the selection range. |
| if (end.x < bounds.left) return false |
| |
| // When the end of the selection is on the top of the composable, and the not on the right |
| // of the composable, the composable is outside of the selection range. |
| if (end.y < bounds.top && end.x < bounds.right) return false |
| |
| // When the start of the selection is on the right of the composable, the composable is outside |
| // of the selection range. |
| if (start.x >= bounds.right) return false |
| |
| // When the start of the selection is below the composable, and not on the left of the |
| // composable, the composable is outside of the selection range. |
| if (start.y >= bounds.bottom && start.x >= bounds.left) return false |
| |
| return true |
| } |
| |
| override fun areHandlesCrossed( |
| bounds: Rect, |
| start: PxPosition, |
| end: PxPosition |
| ): Boolean { |
| if (start.x >= bounds.left && start.x < bounds.right && |
| end.x >= bounds.left && end.x < bounds.right |
| ) { |
| // When the start and end of the selection are in the same column of widgets, |
| // check if y coordinates of the start and end are crossed each other. |
| return start.y > end.y |
| } else { |
| // When the start and end of the selection are not in the same column of widgets, |
| // check if x coordinates of the start and end are crossed each other. |
| return start.x > end.x |
| } |
| } |
| }; |
| |
| /** |
| * Decides if Composable which has [bounds], should be accepted by the selection and |
| * change its selected state for a selection that starts at [start] and ends at [end]. |
| * |
| * @param bounds Composable bounds of the widget to be checked. |
| * @param start The start coordinates of the selection, in SelectionContainer range. |
| * @param end The end coordinates of the selection, in SelectionContainer range. |
| */ |
| internal abstract fun isSelected( |
| bounds: Rect, |
| start: PxPosition, |
| end: PxPosition |
| ): Boolean |
| |
| /** |
| * Decides if the [start] and [end] handles of the selection are crossed around a Composable |
| * which has [bounds]. |
| * When the end handle is visually crossed the start handle, return true. |
| * |
| * @param bounds Composable bounds of the widget to be checked. |
| * @param start The start coordinates of the selection, in SelectionContainer range. |
| * @param end The end coordinates of the selection, in SelectionContainer range. |
| */ |
| internal abstract fun areHandlesCrossed( |
| bounds: Rect, |
| start: PxPosition, |
| end: PxPosition |
| ): Boolean |
| } |
