QtLayout.java

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// Copyright (C) 2023 The Qt Company Ltd.
// Copyright (C) 2012 BogDan Vatra <bogdan@kde.org>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
package org.qtproject.qt.android;
 
import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
 
class QtLayout extends ViewGroup {
 
    QtLayout(Context context)
    {
        this(context, View.generateViewId());
    }
 
    QtLayout(Context context, int viewId)
    {
        super(context);
        setId(viewId);
    }
 
    QtLayout(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        if (getId() == View.NO_ID)
            setId(View.generateViewId());
    }
 
    QtLayout(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
        if (getId() == View.NO_ID)
            setId(View.generateViewId());
    }
 
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        int count = getChildCount();
 
        int maxHeight = 0;
        int maxWidth = 0;
 
        // Find out how big everyone wants to be
        measureChildren(widthMeasureSpec, heightMeasureSpec);
 
        // Find rightmost and bottom-most child
        for (int i = 0; i < count; i++) {
            View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                int childRight;
                int childBottom;
 
                if (child.getLayoutParams() instanceof QtLayout.LayoutParams) {
                    QtLayout.LayoutParams lp
                            = (QtLayout.LayoutParams) child.getLayoutParams();
                    childRight = lp.x + child.getMeasuredWidth();
                    childBottom = lp.y + child.getMeasuredHeight();
                } else {
                    childRight = child.getMeasuredWidth();
                    childBottom = child.getMeasuredHeight();
                }
 
                maxWidth = Math.max(maxWidth, childRight);
                maxHeight = Math.max(maxHeight, childBottom);
            }
        }
 
        // Check against minimum height and width
        maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight());
        maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
 
        setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec),
                resolveSize(maxHeight, heightMeasureSpec));
    }

    @Override
    protected ViewGroup.LayoutParams generateDefaultLayoutParams()
    {
        return new LayoutParams(android.view.ViewGroup.LayoutParams.WRAP_CONTENT,
                                android.view.ViewGroup.LayoutParams.WRAP_CONTENT,
                                0,
                                0);
    }
 
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b)
    {
        int count = getChildCount();
        for (int i = 0; i < count; i++) {
            View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                QtLayout.LayoutParams lp =
                        (QtLayout.LayoutParams) child.getLayoutParams();
 
                int childLeft = lp.x;
                int childTop = lp.y;
                int childRight = (lp.width == ViewGroup.LayoutParams.MATCH_PARENT) ?
                                 r - l : childLeft + child.getMeasuredWidth();
                int childBottom = (lp.height == ViewGroup.LayoutParams.MATCH_PARENT) ?
                                 b - t : childTop + child.getMeasuredHeight();
                child.layout(childLeft, childTop, childRight, childBottom);
            }
        }
    }
 
    // Override to allow type-checking of LayoutParams.
    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p)
    {
        return p instanceof QtLayout.LayoutParams;
    }
 
    @Override
    protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p)
    {
        return new LayoutParams(p);
    }

    static class LayoutParams extends ViewGroup.LayoutParams
    {
        int x;
        int y;

        LayoutParams(int width, int height, int x, int y)
        {
            super(width, height);
            this.x = x;
            this.y = y;
        }
 
        LayoutParams(int width, int height)
        {
            super(width, height);
        }

        LayoutParams(ViewGroup.LayoutParams source)
        {
            super(source);
        }
    }
 
    void moveChild(View view, int index)
    {
        if (view == null)
            return;
 
        if (indexOfChild(view) == -1)
            return;
 
        detachViewFromParent(view);
        requestLayout();
        invalidate();
        attachViewToParent(view, index, view.getLayoutParams());
    }

    void setLayoutParams(final View childView,
                                final ViewGroup.LayoutParams params,
                                final boolean forceRedraw)
    {
        // Invalid view
        if (childView == null)
            return;
 
        // Invalid params
        if (!checkLayoutParams(params))
            return;
 
        final ViewParent parent = childView.getParent();
 
        // View is already in the layout and can therefore be updated
        final boolean canUpdate = (this == parent);
 
        if (canUpdate) {
            childView.setLayoutParams(params);
            if (forceRedraw)
                invalidate();
        } else {
            // If the parent was already set it need to be removed first
            if (parent instanceof ViewGroup)
                ((ViewGroup)parent).removeView(childView);
            addView(childView, params);
        }
    }
}