| /* |
| * 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.compose.ui.text.input |
| |
| import androidx.compose.ui.text.InternalTextApi |
| import androidx.ui.util.annotation.VisibleForTesting |
| import androidx.compose.ui.text.TextRange |
| |
| /** |
| * The core editing implementation |
| * |
| * This class accepts latest text edit state from developer and also receives edit operations from |
| * IME. |
| * |
| * @suppress |
| */ |
| @InternalTextApi |
| class EditProcessor { |
| |
| // The previous editor state we passed back to the user of this class. |
| @VisibleForTesting |
| internal var mPreviousState: TextFieldValue? = null |
| private set |
| |
| // The editing buffer used for applying editor commands from IME. |
| private var mBuffer: EditingBuffer = |
| EditingBuffer(initialText = "", initialSelection = TextRange.Zero) |
| |
| /** |
| * Must be called whenever new editor model arrives. |
| * |
| * This method updates the internal editing buffer with the given editor model. |
| * This method may tell the IME about the selection offset changes or extracted text changes. |
| */ |
| fun onNewState( |
| model: TextFieldValue, |
| textInputService: TextInputService?, |
| token: InputSessionToken |
| ) { |
| if (mPreviousState !== model) { |
| mBuffer = EditingBuffer( |
| initialText = model.text, |
| initialSelection = model.selection) |
| } |
| |
| mPreviousState = model |
| textInputService?.onStateUpdated(token, model) |
| } |
| |
| /** |
| * Must be called whenever new edit operations sent from IMEs arrives. |
| * |
| * This method updates internal editing buffer with the given edit operations and returns the |
| * latest editor state representation of the editing buffer. |
| */ |
| fun onEditCommands(ops: List<EditOperation>): TextFieldValue { |
| ops.forEach { it.process(mBuffer) } |
| |
| val newState = TextFieldValue( |
| text = mBuffer.toString(), |
| selection = TextRange(mBuffer.selectionStart, mBuffer.selectionEnd), |
| composition = if (mBuffer.hasComposition()) { |
| TextRange(mBuffer.compositionStart, mBuffer.compositionEnd) |
| } else { |
| null |
| }) |
| |
| mPreviousState = newState |
| return newState |
| } |
| } |