androidx.annotation.DimenRes#androidx.core.view.MarginLayoutParamsCompat源码实例Demo

private void resetChildMargins(int childIndex) {
  if (getChildCount() == 0 || childIndex == -1) {
    return;
  }

  MaterialButton currentButton = getChildButton(childIndex);
  LayoutParams params = (LayoutParams) currentButton.getLayoutParams();
  if (getOrientation() == VERTICAL) {
    params.topMargin = 0;
    params.bottomMargin = 0;
    return;
  }

  MarginLayoutParamsCompat.setMarginEnd(params, 0);
  MarginLayoutParamsCompat.setMarginStart(params, 0);
  params.leftMargin = 0;
  params.rightMargin = 0;
}
 

/**
 * Whether the character counter functionality is enabled or not in this layout.
 *
 * @attr ref com.google.android.material.R.styleable#TextInputLayout_counterEnabled
 */
public void setCounterEnabled(boolean enabled) {
  if (counterEnabled != enabled) {
    if (enabled) {
      counterView = new AppCompatTextView(getContext());
      counterView.setId(R.id.textinput_counter);
      if (typeface != null) {
        counterView.setTypeface(typeface);
      }
      counterView.setMaxLines(1);
      indicatorViewController.addIndicator(counterView, COUNTER_INDEX);
      MarginLayoutParamsCompat.setMarginStart(
          (MarginLayoutParams) counterView.getLayoutParams(),
          getResources().getDimensionPixelOffset(R.dimen.mtrl_textinput_counter_margin_start));
      updateCounterTextAppearanceAndColor();
      updateCounter();
    } else {
      indicatorViewController.removeIndicator(counterView, COUNTER_INDEX);
      counterView = null;
    }
    counterEnabled = enabled;
  }
}
 

public void setTabButtonVisible(boolean visible) {
    RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams)
            mSendText.getLayoutParams();
    if (visible) {
        MarginLayoutParamsCompat.setMarginStart(layoutParams, 0);
        mTabIcon.setVisibility(View.VISIBLE);
    } else {
        MarginLayoutParamsCompat.setMarginStart(layoutParams, mContext.getResources()
                .getDimensionPixelSize(R.dimen.message_edit_text_margin_left));
        mTabIcon.setVisibility(View.GONE);
    }
    mSendText.setLayoutParams(layoutParams);
}
 

@Override
public void customizeRadioButton(AppCompatRadioButton button) {
  button.setText(contentDescription);
  LinearLayout.LayoutParams size =
      new LinearLayout.LayoutParams(
          LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
  MarginLayoutParamsCompat.setMarginEnd(
      size, button.getResources().getDimensionPixelSize(R.dimen.theme_switcher_radio_spacing));
  button.setLayoutParams(size);
}
 

/**
 * Sets a negative marginStart on all but the first child, if two adjacent children both have a
 * stroke width greater than 0. This prevents a double-width stroke from being drawn for two
 * adjacent stroked children, and instead draws the adjacent strokes directly on top of each
 * other.
 *
 * <p>The negative margin adjustment amount will be equal to the smaller of the two adjacent
 * stroke widths.
 *
 * <p>Also rearranges children such that they are shown in the correct visual order.
 */
private void adjustChildMarginsAndUpdateLayout() {
  int firstVisibleChildIndex = getFirstVisibleChildIndex();
  if (firstVisibleChildIndex == -1) {
    return;
  }

  for (int i = firstVisibleChildIndex + 1; i < getChildCount(); i++) {
    // Only adjusts margins if both adjacent children are MaterialButtons
    MaterialButton currentButton = getChildButton(i);
    MaterialButton previousButton = getChildButton(i - 1);

    // Calculates the margin adjustment to be the smaller of the two adjacent stroke widths
    int smallestStrokeWidth =
        Math.min(currentButton.getStrokeWidth(), previousButton.getStrokeWidth());

    LayoutParams params = buildLayoutParams(currentButton);
    if (getOrientation() == HORIZONTAL) {
      MarginLayoutParamsCompat.setMarginEnd(params, 0);
      MarginLayoutParamsCompat.setMarginStart(params, -smallestStrokeWidth);
    } else {
      params.bottomMargin = 0;
      params.topMargin = -smallestStrokeWidth;
    }

    currentButton.setLayoutParams(params);
  }

  resetChildMargins(firstVisibleChildIndex);
}
 

static int getMarginStart(View v) {
  if (v == null) {
    return 0;
  }
  ViewGroup.MarginLayoutParams lp = (ViewGroup.MarginLayoutParams) v.getLayoutParams();
  return MarginLayoutParamsCompat.getMarginStart(lp);
}
 

static int getMarginEnd(View v) {
  if (v == null) {
    return 0;
  }
  ViewGroup.MarginLayoutParams lp = (ViewGroup.MarginLayoutParams) v.getLayoutParams();
  return MarginLayoutParamsCompat.getMarginEnd(lp);
}
 

static int getMarginHorizontally(View v) {
  if (v == null) {
    return 0;
  }
  ViewGroup.MarginLayoutParams lp = (ViewGroup.MarginLayoutParams) v.getLayoutParams();
  return MarginLayoutParamsCompat.getMarginStart(lp) + MarginLayoutParamsCompat.getMarginEnd(lp);
}
 

private void setMarginStart(View view, @DimenRes int marginResId) {
  int margin = getResources().getDimensionPixelOffset(marginResId);
  MarginLayoutParams layoutParams = (MarginLayoutParams) view.getLayoutParams();
  MarginLayoutParamsCompat.setMarginStart(layoutParams, margin);
}
 

@Override
protected void onLayout(boolean sizeChanged, int left, int top, int right, int bottom) {
  if (getChildCount() == 0) {
    // Do not re-layout when there are no children.
    rowCount = 0;
    return;
  }
  rowCount = 1;

  boolean isRtl = ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL;
  int paddingStart = isRtl ? getPaddingRight() : getPaddingLeft();
  int paddingEnd = isRtl ? getPaddingLeft() : getPaddingRight();
  int childStart = paddingStart;
  int childTop = getPaddingTop();
  int childBottom = childTop;
  int childEnd;

  final int maxChildEnd = right - left - paddingEnd;

  for (int i = 0; i < getChildCount(); i++) {
    View child = getChildAt(i);

    if (child.getVisibility() == View.GONE) {
      child.setTag(R.id.row_index_key, -1);
      continue;
    }

    LayoutParams lp = child.getLayoutParams();
    int startMargin = 0;
    int endMargin = 0;
    if (lp instanceof MarginLayoutParams) {
      MarginLayoutParams marginLp = (MarginLayoutParams) lp;
      startMargin = MarginLayoutParamsCompat.getMarginStart(marginLp);
      endMargin = MarginLayoutParamsCompat.getMarginEnd(marginLp);
    }

    childEnd = childStart + startMargin + child.getMeasuredWidth();

    if (!singleLine && (childEnd > maxChildEnd)) {
      childStart = paddingStart;
      childTop = childBottom + lineSpacing;
      rowCount++;
    }
    child.setTag(R.id.row_index_key, rowCount - 1);

    childEnd = childStart + startMargin + child.getMeasuredWidth();
    childBottom = childTop + child.getMeasuredHeight();

    if (isRtl) {
      child.layout(
          maxChildEnd - childEnd, childTop, maxChildEnd - childStart - startMargin, childBottom);
    } else {
      child.layout(childStart + startMargin, childTop, childEnd, childBottom);
    }

    childStart += (startMargin + endMargin + child.getMeasuredWidth()) + itemSpacing;
  }
}
 

private void updateTextAndIcon(
    @Nullable final TextView textView, @Nullable final ImageView iconView) {
  final Drawable icon =
      (tab != null && tab.getIcon() != null)
          ? DrawableCompat.wrap(tab.getIcon()).mutate()
          : null;
  final CharSequence text = tab != null ? tab.getText() : null;

  if (iconView != null) {
    if (icon != null) {
      iconView.setImageDrawable(icon);
      iconView.setVisibility(VISIBLE);
      setVisibility(VISIBLE);
    } else {
      iconView.setVisibility(GONE);
      iconView.setImageDrawable(null);
    }
  }

  final boolean hasText = !TextUtils.isEmpty(text);
  if (textView != null) {
    if (hasText) {
      textView.setText(text);
      if (tab.labelVisibilityMode == TAB_LABEL_VISIBILITY_LABELED) {
        textView.setVisibility(VISIBLE);
      } else {
        textView.setVisibility(GONE);
      }
      setVisibility(VISIBLE);
    } else {
      textView.setVisibility(GONE);
      textView.setText(null);
    }
  }

  if (iconView != null) {
    MarginLayoutParams lp = ((MarginLayoutParams) iconView.getLayoutParams());
    int iconMargin = 0;
    if (hasText && iconView.getVisibility() == VISIBLE) {
      // If we're showing both text and icon, add some margin bottom to the icon
      iconMargin = (int) ViewUtils.dpToPx(getContext(), DEFAULT_GAP_TEXT_ICON);
    }
    if (inlineLabel) {
      if (iconMargin != MarginLayoutParamsCompat.getMarginEnd(lp)) {
        MarginLayoutParamsCompat.setMarginEnd(lp, iconMargin);
        lp.bottomMargin = 0;
        // Calls resolveLayoutParams(), necessary for layout direction
        iconView.setLayoutParams(lp);
        iconView.requestLayout();
      }
    } else {
      if (iconMargin != lp.bottomMargin) {
        lp.bottomMargin = iconMargin;
        MarginLayoutParamsCompat.setMarginEnd(lp, 0);
        // Calls resolveLayoutParams(), necessary for layout direction
        iconView.setLayoutParams(lp);
        iconView.requestLayout();
      }
    }
  }

  final CharSequence contentDesc = tab != null ? tab.contentDesc : null;
  TooltipCompat.setTooltipText(this, hasText ? null : contentDesc);
}