GuidelineReference.java
/*
* Copyright (C) 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.constraintlayout.core.widgets.analyzer;
import androidx.constraintlayout.core.widgets.ConstraintWidget;
import androidx.constraintlayout.core.widgets.Guideline;
class GuidelineReference extends WidgetRun {
public GuidelineReference(ConstraintWidget widget) {
super(widget);
widget.horizontalRun.clear();
widget.verticalRun.clear();
this.orientation = ((Guideline) widget).getOrientation();
}
@Override
void clear() {
start.clear();
}
@Override
void reset() {
start.resolved = false;
end.resolved = false;
}
@Override
boolean supportsWrapComputation() {
return false;
}
private void addDependency(androidx.constraintlayout.core.widgets.analyzer.DependencyNode node) {
start.dependencies.add(node);
node.targets.add(start);
}
@Override
public void update(Dependency dependency) {
if (!start.readyToSolve) {
return;
}
if (start.resolved) {
return;
}
// ready to solve, centering.
androidx.constraintlayout.core.widgets.analyzer.DependencyNode startTarget = start.targets.get(0);
Guideline guideline = (Guideline) widget;
int startPos = (int) (0.5f + startTarget.value * guideline.getRelativePercent());
start.resolve(startPos);
}
@Override
void apply() {
Guideline guideline = (Guideline) widget;
int relativeBegin = guideline.getRelativeBegin();
int relativeEnd = guideline.getRelativeEnd();
float percent = guideline.getRelativePercent();
if (guideline.getOrientation() == ConstraintWidget.VERTICAL) {
if (relativeBegin != -1) {
start.targets.add(widget.mParent.horizontalRun.start);
widget.mParent.horizontalRun.start.dependencies.add(start);
start.margin = relativeBegin;
} else if (relativeEnd != -1) {
start.targets.add(widget.mParent.horizontalRun.end);
widget.mParent.horizontalRun.end.dependencies.add(start);
start.margin = -relativeEnd;
} else {
start.delegateToWidgetRun = true;
start.targets.add(widget.mParent.horizontalRun.end);
widget.mParent.horizontalRun.end.dependencies.add(start);
}
// FIXME -- if we move the DependencyNode directly in the ConstraintAnchor we'll be good.
addDependency(widget.horizontalRun.start);
addDependency(widget.horizontalRun.end);
} else {
if (relativeBegin != -1) {
start.targets.add(widget.mParent.verticalRun.start);
widget.mParent.verticalRun.start.dependencies.add(start);
start.margin = relativeBegin;
} else if (relativeEnd != -1) {
start.targets.add(widget.mParent.verticalRun.end);
widget.mParent.verticalRun.end.dependencies.add(start);
start.margin = -relativeEnd;
} else {
start.delegateToWidgetRun = true;
start.targets.add(widget.mParent.verticalRun.end);
widget.mParent.verticalRun.end.dependencies.add(start);
}
// FIXME -- if we move the DependencyNode directly in the ConstraintAnchor we'll be good.
addDependency(widget.verticalRun.start);
addDependency(widget.verticalRun.end);
}
}
@Override
public void applyToWidget() {
Guideline guideline = (Guideline) widget;
if (guideline.getOrientation() == ConstraintWidget.VERTICAL) {
widget.setX(start.value);
} else {
widget.setY(start.value);
}
}
}