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Simplify state management in the Android text editing plugin (flutter…
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…#3769)

In particular, this avoids some unnecessary calls to InputMethodManager.restartInput
that caused noticeable lag when moving the cursor.

Fixes flutter/flutter#9928
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@jason-simmons
jason-simmons authored Jun 14, 2017
1 parent 06c91ff commit 834fb96
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Showing 3 changed files with 111 additions and 72 deletions.
109 changes: 76 additions & 33 deletions shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,9 +4,11 @@

package io.flutter.plugin.editing;

import android.content.Context;
import android.text.Editable;
import android.text.Selection;
import android.view.inputmethod.BaseInputConnection;
import android.view.inputmethod.InputMethodManager;
import android.view.KeyEvent;

import io.flutter.plugin.common.MethodChannel;
Expand All @@ -17,63 +19,104 @@
import java.util.Map;

class InputConnectionAdaptor extends BaseInputConnection {
private final FlutterView mFlutterView;
private final int mClient;
private final TextInputPlugin mPlugin;
private final MethodChannel mFlutterChannel;
private final Map<String, Object> mOutgoingState;
private final Editable mEditable;
private int mBatchCount;
private InputMethodManager mImm;

public InputConnectionAdaptor(FlutterView view, int client,
TextInputPlugin plugin, MethodChannel flutterChannel) {
MethodChannel flutterChannel, Editable editable) {
super(view, true);
mFlutterView = view;
mClient = client;
mPlugin = plugin;
mFlutterChannel = flutterChannel;
mOutgoingState = new HashMap<>();
mEditable = editable;
mBatchCount = 0;
mImm = (InputMethodManager) view.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
}

// Send the current state of the editable to Flutter.
private void updateEditingState() {
final Editable content = getEditable();
mOutgoingState.put("text", content.toString());
mOutgoingState.put("selectionBase", Selection.getSelectionStart(content));
mOutgoingState.put("selectionExtent", Selection.getSelectionEnd(content));
mOutgoingState.put("composingBase", BaseInputConnection.getComposingSpanStart(content));
mOutgoingState.put("composingExtent", BaseInputConnection.getComposingSpanEnd(content));
mFlutterChannel.invokeMethod("TextInputClient.updateEditingState", Arrays
.asList(mClient, mOutgoingState));
mPlugin.setLatestEditingState(mOutgoingState);
// If the IME is in the middle of a batch edit, then wait until it completes.
if (mBatchCount > 0)
return;

int selectionStart = Selection.getSelectionStart(mEditable);
int selectionEnd = Selection.getSelectionEnd(mEditable);
int composingStart = BaseInputConnection.getComposingSpanStart(mEditable);
int composingEnd = BaseInputConnection.getComposingSpanEnd(mEditable);

mImm.updateSelection(mFlutterView,
selectionStart, selectionEnd,
composingStart, composingEnd);

HashMap<Object, Object> state = new HashMap<Object, Object>();
state.put("text", mEditable.toString());
state.put("selectionBase", selectionStart);
state.put("selectionExtent", selectionEnd);
state.put("composingBase", composingStart);
state.put("composingExtent", composingEnd);
mFlutterChannel.invokeMethod("TextInputClient.updateEditingState",
Arrays.asList(mClient, state));
}

@Override
public Editable getEditable() {
return mEditable;
}

@Override
public boolean beginBatchEdit() {
mBatchCount++;
return super.beginBatchEdit();
}

@Override
public boolean endBatchEdit() {
boolean result = super.endBatchEdit();
mBatchCount--;
updateEditingState();
return result;
}

@Override
public boolean commitText(CharSequence text, int newCursorPosition) {
final boolean result = super.commitText(text, newCursorPosition);
boolean result = super.commitText(text, newCursorPosition);
updateEditingState();
return result;
}

@Override
public boolean deleteSurroundingText(int beforeLength, int afterLength) {
final boolean result = super.deleteSurroundingText(beforeLength, afterLength);
boolean result = super.deleteSurroundingText(beforeLength, afterLength);
updateEditingState();
return result;
}

@Override
public boolean setComposingRegion(int start, int end) {
final boolean result = super.setComposingRegion(start, end);
boolean result = super.setComposingRegion(start, end);
updateEditingState();
return result;
}

@Override
public boolean setComposingText(CharSequence text, int newCursorPosition) {
final boolean result = super.setComposingText(text, newCursorPosition);
boolean result;
if (text.length() == 0) {
result = super.commitText(text, newCursorPosition);
} else {
result = super.setComposingText(text, newCursorPosition);
}
updateEditingState();
return result;
}

@Override
public boolean setSelection(int start, int end) {
final boolean result = super.setSelection(start, end);
boolean result = super.setSelection(start, end);
updateEditingState();
return result;
}
Expand All @@ -82,26 +125,26 @@ public boolean setSelection(int start, int end) {
public boolean sendKeyEvent(KeyEvent event) {
final boolean result = super.sendKeyEvent(event);
if (event.getAction() == KeyEvent.ACTION_UP) {
// Weird special case. This method is (sometimes) called for the backspace key in 2
// situations:
// 1. There is no selection. In that case, we want to delete the previous character.
// 2. There is a selection. In that case, we want to delete the selection.
// event.getNumber() is 0, and commitText("", 1) will do what we want.
if (event.getKeyCode() == KeyEvent.KEYCODE_DEL &&
optInt("selectionBase", -1) == optInt("selectionExtent", -1)) {
deleteSurroundingText(1, 0);
if (event.getKeyCode() == KeyEvent.KEYCODE_DEL) {
int selStart = Selection.getSelectionStart(mEditable);
int selEnd = Selection.getSelectionEnd(mEditable);
if (selEnd > selStart) {
// Delete the selection.
Selection.setSelection(mEditable, selStart);
deleteSurroundingText(0, selEnd - selStart);
} else if (selStart > 0) {
// Delete to the left of the cursor.
Selection.setSelection(mEditable, selStart - 1);
deleteSurroundingText(0, 1);
}
} else {
String text = event.getNumber() == 0 ? "" : String.valueOf(event.getNumber());
commitText(text, 1);
// Enter a character.
commitText(String.valueOf(event.getNumber()), 1);
}
}
return result;
}

private int optInt(String key, int defaultValue) {
return mOutgoingState.containsKey(key) ? (Integer) mOutgoingState.get(key) : defaultValue;
}

@Override
public boolean performEditorAction(int actionCode) {
// TODO(abarth): Support more actions.
Expand Down
72 changes: 34 additions & 38 deletions shell/platform/android/io/flutter/plugin/editing/TextInputPlugin.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,10 @@

import android.app.Activity;
import android.content.Context;
import android.text.Editable;
import android.text.InputType;
import android.text.Selection;
import android.view.inputmethod.BaseInputConnection;
import android.view.inputmethod.EditorInfo;
import android.view.inputmethod.InputConnection;
import android.view.inputmethod.InputMethodManager;
Expand All @@ -29,16 +32,16 @@
*/
public class TextInputPlugin implements MethodCallHandler {

private final Activity mActivity;
private final FlutterView mView;
private final InputMethodManager mImm;
private final MethodChannel mFlutterChannel;
private int mClient = 0;
private JSONObject mConfiguration;
private JSONObject mLatestState;
private Editable mEditable;

public TextInputPlugin(Activity activity, FlutterView view) {
mActivity = activity;
public TextInputPlugin(FlutterView view) {
mView = view;
mImm = (InputMethodManager) view.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
mFlutterChannel = new MethodChannel(view, "flutter/textinput",
JSONMethodCodec.INSTANCE);
mFlutterChannel.setMethodCallHandler(this);
Expand Down Expand Up @@ -98,60 +101,53 @@ public InputConnection createInputConnection(FlutterView view, EditorInfo outAtt
throws JSONException {
if (mClient == 0)
return null;

outAttrs.inputType = inputTypeFromTextInputType(mConfiguration.getString("inputType"),
mConfiguration.optBoolean("obscureText"));
if (!mConfiguration.isNull("actionLabel"))
outAttrs.actionLabel = mConfiguration.getString("actionLabel");
outAttrs.imeOptions = EditorInfo.IME_ACTION_DONE | EditorInfo.IME_FLAG_NO_FULLSCREEN;
InputConnectionAdaptor connection = new InputConnectionAdaptor(view, mClient, this,
mFlutterChannel);
if (mLatestState != null) {
int selectionBase = (Integer) mLatestState.get("selectionBase");
int selectionExtent = (Integer) mLatestState.get("selectionExtent");
outAttrs.initialSelStart = selectionBase;
outAttrs.initialSelEnd = selectionExtent;
connection.getEditable().append((String) mLatestState.get("text"));
connection.setSelection(Math.max(selectionBase, 0),
Math.max(selectionExtent, 0));
connection.setComposingRegion((Integer) mLatestState.get("composingBase"),
(Integer) mLatestState.get("composingExtent"));
} else {
outAttrs.initialSelStart = 0;
outAttrs.initialSelEnd = 0;
}

InputConnectionAdaptor connection = new InputConnectionAdaptor(view, mClient, mFlutterChannel, mEditable);
outAttrs.initialSelStart = Math.max(Selection.getSelectionStart(mEditable), 0);
outAttrs.initialSelEnd = Math.max(Selection.getSelectionEnd(mEditable), 0);

return connection;
}

private void showTextInput(FlutterView view) {
InputMethodManager imm =
(InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
imm.showSoftInput(view, 0);
mImm.showSoftInput(view, 0);
}

private void hideTextInput(FlutterView view) {
InputMethodManager imm =
(InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getApplicationWindowToken(), 0);
mImm.hideSoftInputFromWindow(view.getApplicationWindowToken(), 0);
}

private void setTextInputClient(FlutterView view, int client, JSONObject configuration) {
mLatestState = null;
mClient = client;
mConfiguration = configuration;
InputMethodManager imm =
(InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
imm.restartInput(view);
}
mEditable = Editable.Factory.getInstance().newEditable("");

private void setTextInputEditingState(FlutterView view, JSONObject state) {
mLatestState = state;
InputMethodManager imm =
(InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
imm.restartInput(view);
mImm.restartInput(view);
}

void setLatestEditingState(Map<String, Object> state) {
mLatestState = (JSONObject) JSONUtil.wrap(state);
private void setTextInputEditingState(FlutterView view, JSONObject state)
throws JSONException {
if (state.getString("text").equals(mEditable.toString())) {
Selection.setSelection(mEditable, state.getInt("selectionBase"),
state.getInt("selectionExtent"));
mImm.updateSelection(
mView,
Math.max(Selection.getSelectionStart(mEditable), 0),
Math.max(Selection.getSelectionEnd(mEditable), 0),
BaseInputConnection.getComposingSpanStart(mEditable),
BaseInputConnection.getComposingSpanEnd(mEditable));
} else {
mEditable.replace(0, mEditable.length(), state.getString("text"));
Selection.setSelection(mEditable, state.getInt("selectionBase"),
state.getInt("selectionExtent"));
mImm.restartInput(view);
}
}

private void clearTextInputClient() {
Expand Down
2 changes: 1 addition & 1 deletion shell/platform/android/io/flutter/view/FlutterView.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -174,7 +174,7 @@ public void surfaceDestroyed(SurfaceHolder holder) {
"flutter/platform", JSONMethodCodec.INSTANCE);
flutterPlatformChannel.setMethodCallHandler(platformPlugin);
addActivityLifecycleListener(platformPlugin);
mTextInputPlugin = new TextInputPlugin((Activity) getContext(), this);
mTextInputPlugin = new TextInputPlugin(this);

setLocale(getResources().getConfiguration().locale);

Expand Down

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